Declining quality of copper line, Telkom delaying repairs

The only reason I feel I need to escalate through HelloPeter, is the fact that after so many calls to my ISP, having several technicians perform apparent "fixes" to my line, in the end, the line just decays further.

TL;DR (Too long; Didn't read) My Telkom Line is beyond messed up, the line leaving my house needs replacing immediately and several technicians have been unable to make a long term fix. I refuse to wait up to 3 months for a line replacement as Fibre is not coming to my neigbourhood any time soon!

This whole mess started a year ago when I changed ISP's (and no, they are not to blame), and as the months swept by the problem was becoming more and more unavoidable.

I live in an old neighbourhood (sadly one that isn't maintained by Telkom), by mere fact the last time Telkom replaced all the copper was in excess of 30 years ago. Patching faulty lines worked for some residents, but mine was always temporary to the tune of a few months Max!

I have a 20mbps line and I'm physically less than 150m from an exchange, copper-wise I'm less than 800m meaning I can (and have had) full line speed with a terrific 7ms ping, about a year ago.

I've had technicians "fix" my line, and replace some copper in the house, this didn't solve anything as my SNR continued to drop. More recently I had a technician fix an earth fault that cleared the noise on the line of half the neighbourhood (he spent almost 3 days on this issue).

After this fix, it bumped my SNR up to a delightful 7 (as 6 is the bare minimum) from a terrible 5.2. He also got my ping back to 9ms and speeds were looking good, all the way up to a stable 16mbps.

Unfortunately days after, the line went sour again, he tested and found a DC voltage, proceeded to check all the way from the exchange to our nearest ground port, and found the SNR drops from 13db down to 6 there, so the fault lies between the 30 year old copper leaving my house and reaching that ground port. Telkom had no "spare" lines, and the noise is currently so bad that you cannot hear anyone, ADSL cuts off when the phone is in use, and calls drop. This is no longer purely an ADSL issue, it is a Telkom Line rental issue that needs to be solved!

I confirmed with my neighbours to split of the street pole, their lines are clear and speeds aren't to terrible. Yet I'm stuck with an unusable voice line and terrible jiggle making streaming and gaming impossible!