Welcome to the Community, I'm very sorry to learn about the problems you're experiencing with your telephone line at the moment.
I've been able to locate your account and run some tests on the set top box from our end for you, we're not detecting any errors at the moment though. I hope this means things are working as they should?
If not, have you been able to test your handset at all? By trying an alternate handset or your handset on an alternate line?