Although this is an uncapped ADSL issue listed below, it seems that all these 'specials' & 'promotions' are pointless if their infrastructure is taking a strain.
I mean whats the point of paying for something when you cannot deliver any speed?
From their website for network status :-
High Demand in Southern and Eastern Regions
We are experiencing high network demand in the South and East (Cape Town, Port Elizabeth and Durban), resulting in real time services being affected on Uncapped accounts. This infrastructure is expected to be upgraded within 3 weeks, which will resolve the congestion. We appreciate your understanding whilst we await completion of the upgrade.