I'm very sorry to learn about the problems you're experiencing with your phone line at the moment. I've also responded to your other thread but thought I'd respond here as it's your original post
I've been able to locate your account to run some tests on the line from our end for you, we're seeing a problem in your local area (Reference F004830042) which is causing these issues.
We're expecting this to be resolved later today, so if you're still experiencing the issue tonight, get back in touch and we'll take another look. Apologies again for the inconvenience this issue is causing, we're looking forward to putting it right.