I'm really sorry to hear that you've been experiencing some issues with your phone line, and I'd really like to help you out.
I've done some investigations on your line, and can see no reason why you should be experiencing this fault. We are not currently aware of any issues locally, and the testing I have done has not shown any abnormalities on the line.
So I'd now have to look at this and an individual issue. Have you been able to eliminate the phone from being at fault, either by trying another phone on the line, or by trying your phone in a known working line. I ask this as once you're able to confirm this the next step would be to arrange for a technician to call out and investigate further.
I've sent you a private message in order to get the ball rolling with 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.