It is important to work out if the problem is the line losing sync or not, by looking at the LED on your router that would indicate a loss of sync. If so, it is very much a local Telkom issue, and an intermittent problem. NOT fun getting it fixed - see some of my experiences here:
http://mybroadband.co.za/vb/showthread.php?t=44388
Of course, when they do that remote test, the line happens to be fine and you get fobbed off.
It took me 5 or 6 logged faults until I got a competent local tech who has mostly sorted out the problem. Some advice:
1. Insist that it is an "intermittent" fault and get a fault reference - write this down.
2. Bug them daily about the fault reference.
3. When it looks fixed DO NOT sign off the fault with the tech or when they call you - again insist it is intermittent and only allow them to close the fault after a week or so of fault-free operation.
4. The techs often do not understand things like attenuation - nor do I really, but when the tech says you are too far from the exchange because your attenuation is 30-something, insist that ADSL can run at at least 60!
5. Try to get the number of the local techs or their office or manager and bug them.
LOL - one tech even claimed it was because I was "using all the bandwidth" to the local exchange and was being cut off to give others a chance! On my little 384k line
nogal!
Good luck!