[kwikbreaks]

There's always something that can be done - if it's on the tap with least attenuation already then it needs lower loss coax from the cab - in other words a re-pull. Alternately some amp or other on the way back to the optical node is on the blink and needs replacing. Of course neither solution comes cheap so that's why you aren't getting either.

It may well be that fixing the levels wouldn't solve the problem anyway if it is caused by congestion. The solution to that is even more expensive.

Have you considered upgrading to ADSL? Maybe you should call retentions and tell them you've had enough and if it isn't fixed you'll be doing that.