No Service

Hi everyone,

I was hoping that someone might be able to shine some light on a problem that I have had with my iPhone 4.

I recently tried to switch phone networks on this phone (from O2 to 48) - ever since doing so my phone has displayed "No Service" whenever I put in the sim. Originally I thought that the 48 carrier may not be supported by the phone, but I tried switching back to O2 and this hasn't helped either. I should say that I actually won this phone in a competition in 2010, and when I received the phone it came with a Vodaphone sim. I never used this, however, and for a number of years (until I stupidly tried switching networks) the phone worked perfectly. The sim works in other phones, so I know that it is an issue with the device itself..

I have tried bringing the phone to a shop where they unlock iPhones, in case it had somehow become locked to Vodaphone now, but they said that they couldn't do it because the phone was acting like it was stolen.

I have tried restoring the phone, but to no avail.

I realise that this probably means that there is nothing else that I can do, but if anyone has any ideas I would be grateful.

Thanks,

Steph