Who do you pay line rental to? EE as well?
If you have an NTE5 master socket, where the bottom half of the faceplate comes off if you remove two screws, gently take it off. Gently because there could be wires attached to the back. You'll see a socket behind it, that it plugged into. That is the test socket.
You need to plug a phone, preferably a corded one, into that test socket, (no dangly filter - just the phone plug), and try the Quiet Line Test again. You can get a corded phone for about £5 in many places, even some supermarkets.
If it is quiet, then the problem is your end and should be solvable with help from here.
If it is still noisy, forget about the broadband problem. Bang on about the noise on the phone line, to the line rental people. Don't mention the broadband even as an incidental issue as that lets them off the hook. They have to fix that noise. They don't have to fix this level of broadband problem. Not without you going hairless over the next few weeks anyway.
Fix the phone noise and the broadband goes back to normal in 99.9% of cases.
My broadband basic info/help site - www.robertos.me.uk
| Domains,website and mail hosting - Tsohost
Connection - Plusnet
UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 600m. - BQM
"Where talent is a dwarf, self-esteem is a giant."
- Jean-Antoine Petit-Senn.
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.