I had the same issue a while ago... and i started again today (probably happened due to the storm we had yesterday)
The last time, I logged 3 faults, with no resolution... but then, I figured out what the problem was... It was my attitude.
I called and spoke to the consultant in a polite and calm manner. I gave the reference number and explained that my SNR values hadn't gotten any better.
She then escalated me to a "more advanced" consultant.
That consultant sat with me through the usual "reset your router" tests and bla bla bla... instead of losing my rag and saying that I've done that 400 times already, I was patient and I acted interested in everything the consultant was saying... Kinda made them feel important if you will.
I insinuated that for over 5 years, my 4meg line used to sync at max speed and now the speed had dropped to 1.5mbs... The guy agreed that it was not on...
He said he'd send out a consultant to see if there was any physical damage to my line and will trace it all the way to the exchange... GEE THANKS!
About 4 hours later, I got a call informing me that the DSLAM was struck by lightning at the exchange and they will replace it withing the next 18 hours... I was very skeptical, but I was glad for the feedback. Lo and behold, the next morning, I was syncing at 6.8Mbs with higher SNR numbers than ever before.
What did I learn from this exercise?
If you're hostile to the consultants, they shutdown and they don't apply themselves to your problem. Sure it ain't professional, but it's the real world!
If you want your fault sorted out, ask the consultant to escalate you... if you've already got a reference number and it wasn't sorted out... then just bear with them.
They got a job to do... and I found the guy VERY HELPFUL for a change. my line was sorted out within the day... so chill. instead of going in gun's blazing (my usual style), be a little friendlier and they try sort you out.