The Samsung Omnia – never again, put it that way.

Most of the mobile phones I have owned have been pretty good in terms of reliability and usability. I've owned a basic Nokia and two Sony Ericssons and none of them have caused me any problems. My latest phone is a different story.

The Samsung Omnia is, in my opinion, 'a poor man's iphone' at best, and an infuriating piece of useless plastic at worst.

Unlike a conventional mobile, the Omnia relies upon a touch sensitive, computer-generated representation of a keyboard. In other words, the keys aren't really there at all. 'Dialling' any number requires thought and I don't want to think too much about such a mundane task; I never had to with my other phones. With the Omnia, it's a case of 'dialling' carefully and slowly, using a pen, watching all the time in case, as often happens, the machine inputs, say, half a dozen 3s or 4s – it's that sensitive. Dialling 0208 could easily become 02000008. You get the picture. Not ideal if you're in a hurry.

I know what you're thinking: use the phone's speed dialling function. Under normal circumstances I'd say fine, but not with the Omnia. Problems lurk on every corner for Omnia users. I have stored around a dozen pre-set telephone numbers, but first I have to access them by pressing a small blue keyhole symbol at the top right of the screen. Pre-set numbers are supposed to pop up, but they don't. Instead, I am given a page of icons offering me the web, the camera, media player, alarms, everything but my pre-set numbers. If I press 'exit' to try again, the same thing happens. Then, to add insult to injury, the phone locks itself, meaning that I have to press 'unlock', which is more difficult than you might think. It's virtually impossible to unlock the phone using the pen (of which, more later) so I have to thump the phone hard with my index finger and then start again, but I get greeted with all the unwanted icons for a second time. Arrrggghh!!! The solution is to press another icon at the top of the screen, like 'settings', and then, as the icons shuffle to the left, press the speed dial icon when it has moved to the far left of the screen – that way the pre-set numbers pop up.

Finally I get to my speed dial numbers. Now I've got another problem. If I press the icon for my home number, it accesses the number represented by the icon to its left and I find myself dialling somebody I don't want to talk to; then the problem of stopping the phone dialling a wrong number, which involves a frantic thumping of the black button below the screen to cancel the call. I have numerous calls from one particular work colleague who thinks I am trying to reach him when I'm not.

The Omnia likes to keep me on my toes by constantly inventing new problems. For example, when I press 3 it's 2 so once again I can't simply dial a phone number on the move, I have to stop, concentrate hard, use the pen to tap the 3 key at its far edge in order to key in a 3 and not a 2. This often takes more than one attempt and is further thwarted by the fact that the cancel key (the orange arrow at the top right of the keypad) then types a 3, the key to its immediate left. Try to keep up: the 3 key is really a 2 and the cancel key is really a 3, but there is no way I can cancel the wrong number so I have to quit the keyboard entirely and start again. But then, the phone locks again and I have to thump it hard again with my index finger to unlock it as using the pen, for some inexplicable reason, won't unlock it.

Writing a text message is a nightmare too. Sometimes it works, sometimes not. Invariably, the latter. A big problem with texting is that the keys do not represent the right letters. If I try to write 'Good morning' I need to be aware that G is F and that O is U and that P is really i, D is S and so on. In short, it's impossible so I am forced to give up.

If I try to exit the messaging function, another problem arises: I can't. The pen simply won't work if I use it to depress the 'ok' in the screen's top right hand corner which should close the window. More often than not, a text bubble will appear saying 'contract WAP (GPRS) which I don't understand, but can't delete however hard I try.

The scrolling function on Call Log, Phonebook and Messaging is temperamental, only working effectively when it so chooses. With messaging in particular, it is very hard to move the scroll bar up or down to review messages received or sent, and to exit a message and return to the main list of messages is nigh on impossible, even using the pen, which is supposed to make life easier for Omnia users. It is best to depress the phone icon on the bottom right of the phone and then re-open the function from the phone's 'home' page.

As for the pen, well, it's there to be lost. Miraculously, I still have mine, although it has spent a few days under the car seat during which time I have relied upon assorted ballpoints and my chipolata fingers. The pen is supposed to make things easier, especially dialling and messaging, but it is just another irritation, especially when the P key is O, the G is F and so forth. And I can hit that 'ok' at the top right of the screen as many times as I like but it won't remove the page I'm on for love nor money: all I get is annoying speech bubbles that refuse to go away.

If somebody calls me I have to call them back as, by the time the phone is out of my breast pocket and in my hand, the right way around and without the pen swinging about uncontrollably, they've gone. Even if the phone comes out of my pocket easily enough, I've got to hit the word 'answer' and that's harder than it sounds, believe me; forget using the pen, by the time you've unleashed it from its housing, your caller has hung up. If I call back I'm confronted with the aforementioned call log problems. If I use the speed dial function, I end up calling somebody else. Trying to stop a mis-dialled number is very hard and usually involves a lot of thumping on the screen to avoid a call from somebody else which, if they get through, results in, "Sorry, I dialled you accidentally, new phone," I might lie, ignoring the fact that I've had the Omnia for months.

Knowing what I know about the Samsung Omnia, I would never buy or recommend one to friends. Enemies, maybe. I am seriously considering transferring the SIM card to my old Sony Ericsson and using that instead. Mind you, the Omnia does have a decent 5 mega pixels camera, but that is the phone's only redeeming feature.