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.