I have had a recurring fault on my line for 10 years. BT have said they would look into it only to come back to say they could not find it many, many times . It is a bad connection / noise on the line. The line to the fibra box is only 300 yards long but they say is too expensive to renew even though I pay them around £1000 a year ! It happened again today and they said there is definitely a fault and they will investigate and come back to me - again.