iPad 2 no service

[M1keyb77]

Hi guys first time of posting on here. I have searched but couldn't find anything to help. Basically bought a second hand ipad 2. Devolved a couple of issues so had it replaced at my local apple store. Ipad hadn't been turned on till I got home. Anyway got hold of a new sim from O2 tried it and had the message invalid sim. After a reboot it searched for a network but came up with No service.
I then looked into it further and O2 say I need an ipad sim, so ordered one of those, turned up this morning and inserted the sim and exactly the same. No matter what I do it won't work just keeps saying no service! Have tried all the turning wifi off and flicking it between airplane mode and back.
When I plug it into iTunes on my laptop it says something along the lines of the SIM card is not supported (can't remember 100%)

Any help would be great as its really baffling me. Also tried the sim in my iPhone 4S and it comes up with O2
Obviously can't use it as there's no credit on there.

Thanks in advance guys.

 

[charlituna]

have you tried restoring it and setting it up as new. Might be something glitchy in the software. I would even say do it when Apple calls DFU restore mode.

make sure any data is synced up to the computer, photos imported etc. or icloud is up to date if you were using that.

then plug it into your computer. After it comes up on the screen,halt any syncing that might try to start. Then hold down both the sleep and the home button until it shuts off and disappears from iTunes. As soon as it does that let go of the sleep button but keep holding the home button until it says something about recovery mode and says you need to restore. then go for it.

once it is done restoring see what happens.

 

[M1keyb77]

Yeah I have tried doing that, once it re syncs with iTunes I get a message about the SIM card is not supported and to contact the carrier (or something along those lines) even had apple support run through it with me. I was advised to try another SIM card and if that doesn't work to take my ipad back to apple.