Incorrect Billing and still waiting for feedback

I decided to take the price-lock offer and the 1st 2 months everything went fine. Now for September, my bill is >R100 than normal? I did contact the JHB Head Office and was given a reference ***2#C1 to confirm that a quire was logged and somebody to contact me within the next 24-48 hours. A week has now almost past and still nobody phoned or mailed me. This is just poor service. By looking at other complaints on this website, seems that I am not the only one with billing problems? So when will this be resolved if that is even an option?