O2

I recently got a new phone and needed a new SIM same number and contract. I have received the SIM and put it in my new phone. it doesn’t work. In settings it acknowledges that O2 is the network, but the phone claims it has no service. I can’t receive...

I dropped my old phone and have just got a new one. the new phone takes a different size SIM. How do I order a replacement SIM? I want to stay with O2 and I want to keep my number. How do I get just a new SIM of the correct size?