hi, since returning to the UK from a holiday abroad on 31/12/15 I have had no phone service. It shows emergency calls only and when I try to make a call a message pops up saying not registered on a network!
Welcome to the Virgin Community, I'm really sorry to learn about the problems you've been experienced since getting back to the UK.
You can check to see if the issue is part of an ongoing problem by checking our Mobile Coverage Checker [here]. If there are no reported problems, try switching your phone off then on again, if still the same then we'll try to connect to the network manually.
Doing that depends on what phone you've got, so let me know what you're using and I'll get you some instructions. Lastly, have you tried this in more than one area?