I was having the same problems, frequently loosing synchronization several times a night.
I was eventually able to get a technician to come out, and he replaced some wiring and fiddled around.
Received an sms the next day: 'Your issue has been resolved"
Same problem still occurred, called again and they recommended I downgrade my line even though I stated several times my attenuation and noise levels were fine.
But whatever ok, downgraded from 4mb to 384.
Received an sms the next day: 'Your issue has been resolved"
Still no change, got a nice downgrade bill though.
Called again and the same technician comes out, fiddles around and eventually says to me "You know your speeds won't be as fast at night". I gave him a blank stare and explained to him for the 20th time it had nothing to do with speeds, I was getting disconnected..
He obviously had no idea, so told me he'd replace the DSLAM and then they'll monitor my line.
Received an sms the next day: 'Your issue has been resolved"
I'm still experiencing the same problem, have left 4 messages at their offices for him to call me, because some nights it's basically unusable, nevermind highly annoying.
I'd drop telkom in a second if there was ANY other service that could give me ADSL latency.
/rant