Folks if you've been getting problems since the upgrade, which are problems specific to YOUR line, rather than overall congestion of your EXCHANGE, then I suggest you do the following:
1) Log into your router, and set the modulation to G.DMT (the modulation it was before Telkom installed the new equipment in the exchanges). This can greatly help with stability for some lines!
2) Phone Telkom, and ask that they place you back on 4Mbps profile, or if you have the patience, try 6Mbps first
This sort of problem is inevitable with a DSL speed upgrade, because many people being upgraded are on lines that don't support the higher rates. That doesn't mean you can't easily sort the problem out. The upgrade has good intent - just because your line can't quite handle it doesn't mean the whole thing is a failure - on the contrary, it's very easy to resolve - unless it's an exchange-specific fault.