Call center does not answer

After requesting a line speed upgrade (but seemingly paying for it!), and it just not happening, I requested it again (as well as lodging a billing dispute), but have not received any response. Today I have been trying to contact the call center to follow up, with no success. I have tried 4 times so far, holding on for an average of 30 minutes each time. Very frustrating. There is no indication on how far down the line my call is, in order for me to decide whether it is worth while to hold on. I tried to log in to My Telkom - apparently "they could not id me as a valid contact for this service on this account". I really feel like cancelling the whole service!!