Oh dear O2. Simple questions need simple answers.

My Xperia X10 has been great but lately the need to charge it more than once a day and seemingly random shut-downs when it had way more than 50% charge was getting on my nerves. In a way I am quite glad that I didn't switch my O2 contract to paying a low monthly amount and keeping the phone which is what I probably would have done when my 2 years were up in April. These last few weeks convinced me that I do need another phone, well a battery probably would have done, but the Xperia P looked really nice, is due to get Android's Ice Cream Sandwich now - maybe even Jelly Bean soon - so I set up an upgrade through MyO2 on-line.

That was simple enough and the next day the new phone arrived. In the box was a SIM card which is a two-in-one affair which looks as though it would fit the normal size SIM socket as well as the new microSIM socket. You can break out the microSIM for phones like the Xperia P. As I couldn't transfer my old normal size SIM to the new phone I was wondering how on earth O2 would know that the new SIM was mine. And, presumably, it would have a new number. I suppose if it had been a really really nice new number I might not have minded but the prospect of having to update so many things with a new number wasn't that appealing. A colleague also pointed out that none of the people I'd given cards to or met at various places and scribbled the number down on bits of paper, napkins or hands would ever be able to know the new one.

So, rather than break out the microSIM and stuff it in and hope for the best, I got in touch with O2 via their on-line chat thing. I had tried communicating with Ask Lucy on their site but firstly she only wanted me to type one sentence at a time and secondly appeared just to send me links related to various words she recognised, all of which were useless. The chat worked better and I did get the feeling that 'Diana' understood my query. She said she would send a microSIM in the post which I should use. Well, that seemed simple and I assumed that she would somehow link that one to my account so that when I stuffed it in the phone it would recognise me.

It arrived very promptly the next day, today, and I set about getting the new phone up and running. The fact that I couldn't make calls didn't trouble me as it is a lousy area and that's often the case. GMail and Facebook were almost instantly up and running which was very encouraging. So far so good, I recall posting on Facebook at the time.

Then it told me that a system update was available. Yes, Ice Cream Sandwich already, I thought. Cool. So I plugged it in to the PC which set about downloading the new software. That took ages to get it on the PC and then it was time for the next stage: putting it on the phone. I followed all the instructions but each time it failed so I gave up on that. Try again another day. Over at the PC there was no chance of it getting a connection but putting it back next to the old phone, which did have a connection, I began to wonder about that recognition thing again. Looking in the applications I found the one that would tell me what my number was. No number. Hmm. I looked at Network Provider. None there. It could see O2 was there but wouldn't link me to O2. More or less as I had wondered at the very start.

Back to O2 support on-line. And that's where I spotted something called a SIMswap page. It was billed as the place iPhone users getting the latest iPhone could order these new microSIMs that it said they'd need. Reading on there was a link to a SIMswap page where you entered your number and, although it didn't say so, it looked like the sort of place that would do what I wanted.

I put my number in, entered the code they sent to my (fortunately still going) old phone and that may have done the job. I then got a message on the old phone to say that the switch would take anything between 30 minutes and 24 hours. I would know when it had been effected when my old phone stopped working, the site said. Now, I have no idea when that will be but maybe when I wake up tomorrow I'll have a dead old phone and a live new one.

It'll be fun finding out. But, really O2, you could have made that a whole load simpler by just adding a short paragraph in the box to say "Hey, you've got a phone that needs a microSIM. Your old one won't fit. Stick the new one in and go to our site etc..."

Watch this space. I still have the system upgrade to do!