iPhone 6s locked to three
Hi
i purchased my iPhone 6s through mobiles.co.uk but while waiting for my new sim for the new contract i put my current three sim in. Apparently this has caused my phone to lock to three and now won't accept my new o2 sim.
I Have contacted three who are saying my phone is unlocked to work with all networks and do restore my phone and put my new sim in and it will work. However when I do this I get a message saying sim not valid. Does anyone know how I can get it unlocked so I can start using my new contract?
Thanks
Helen x