If there is noise on the line, then you need to report it as a noisy line. Do not mention the broadband problem, otherwise it will end up in the wrong fault queue, and take much longer to be fixed. There are plenty of people who can fix phone faults, but not as many broadband people.
Once the phone fault is fixed, then the broadband will get better.
You need to eliminate any possible issues with your own internal wiring, by connecting things up as shown below, and see if the noise is still there.