BT are shit...
"Engineers have visited Mr Sampson twice during the last 12 months – in April and July. On both occasions they carried out a successful full test of the local network, without experiencing any issues."
Yeah like the 2 fucking engineers you sent out to a site we supported. Both engineers said the line "had no issues". Then they sent a 3rd. Luckily the 3rd engineer did his job properly and said
"It is showing fine at the bungalow but I'll go down the road and double check the box". And there it fucking was. He said "I've found the issue. The box this line is connected to out on the secluded street is opposite a pub. I think a lorry must of reversed over the box at some point crushing it. Then someone has come to fix it and instead of fixing it properly, just spliced it together so that it would report a "I'm fine" signal. Which of course, then sometimes fails in your case".