Thanks for that DOTLESS50
Have you called into our centres to run diagnostics on the phone line?
We would ask you to be at the property to do this and we may ask you to remove any other equipment connected to the phone line whilst we run this test.
It would of course also be worth calling us off a mobile phone, due to the nature of this issue.
In regards to the BT call, this sounds like a scam call. We've had numerous callers reporting them recently. To attempt stopping these it would be a good idea to get in touch with the telephone preference service on 0345 070 0707
David_Bn