iPad 2 3G constantly has 'No Service' - HELP!

For over a week now no matter where I am my iPad 2 constantly says 'No Service'. I am with 3 but it doesn't seem to be a sim issue, my mom has the iPad 1 on 3G too and both our sim cards work perfectly fine with full bars in her iPad, however when trying them both in mine it still says 'No Service'. At school where I primarily use it I occasionally see the 3 logo after minutes of waving it about but it quickly goes back to No Service before I can access the Internet.
*
This hasn't been constant, I've had the iPad 2 since last May and it has always had full bars in my house and at school. I've tried almost everything I've read online, reset all settings which didn't work, so I completely wiped the iPad as if it was brand new and it still didn't work, I've messed about with all the settings that could be related with this issue but still nothing. The iPad is in very good condition aside one or two minor markings on the back so I wouldn't think it's because the iPad is damaged, help?

Are you with AT&T or Verizon?

I'm in the UK.

Does your iPad use a SIM card to connect to the 3G internet service? You might need a new SIM card from your carrier as they do tend to wear out over time.

It does require a sim card yes however it isn't the sim card that seems to be the problem as my sim card works perfectly fine in my moms iPad which is strange.

If you've ruled out a carrier or SIM prob, that means it's probably an iPad prob. In that case, contact Apple or go to an Apple store while you're still under warranty.

Yes it looks like the only option now, thank you.

hi there im in the EXACT same position as you, did the apple store resolve the problem? and if they did what was it?