@K-123
It sounds like you may need a new sim card or there is a network issue in your local area.
try your sim in a different phone, and see if you get the same, as if you do then check https://status.o2.co.uk and enter your post code.
If all is well, then take photo ID to an o2 store and get a replacement sim card.
Also these guides might help Guide: How can I sort out my network issues?
Guide: Is the network down for me or everyone?
This is not customer services and we dont have access to your account
I do not work for o2 or any VMo2 /Telefonica/Liberty Global Company
