I'd like to start off by welcoming you to the forums, and say that I'm really sorry to hear that you've been having some issues with your phone line.
I've completed some testing on the line, and can see no reason why you should be experiencing these faults at the moment. We are not aware of any local issues, and the line isn't reporting any issues.
So I'd now have to move towards booking someone to call out and investigate further for you, so I'll send you a private message in order to get the wheels in motion on this. Please look to the top right of this page where you'll see a purple envelope icon, click on this and you'll see my message.