If you have tried the self help on this page
and your phone is still not working, then you will just have to wait.
BT do not provide or maintain the external network. This is done by Openreach who work for all service providers. BT do not get any special treatment.
Openreach have a backlog of work, so installation and repairs are taking much longer than normal.
The holiday period would have delayed things as well.
This is a customer to customer forum only, where forum members can help each other with BT Retail products and services.
Anything you post here does not go to BT. Although the forum is moderated by BT, not all post are read.
This link may help.
Ouch. You say the PC also has a fault after a thunderstorm? Sounds like a lightning strike to me. If your phone is out, there could be much more damage at the exchange we dont know about. Good luck and hope the wait is not too long.