Ridiculous Over Charging & False Promises

Cant believe how Vodacom feel they can incorrectly charge their long standing clients and get away with it!!! Im sure they make a killing each month!! Long story short, in December I was charge almost triple what I should of been on my account. , after much arguments and discussion with Vodacom they confirmed they would pay me back two thirds which to date has still not happened. On Saturday I came across the same problem where I have now been charged double what I should pay per month on my account. The consultant I spoke to said I was supposed to be paid about back 2200 odd rand on the 24.02.2015 as this is what there accounts showed was paid into my account. This did not happen, I even double checked my statements!! Now that I need to send through the details to prove them wrong I cannot get anyone to get back to me, same problem yesterday again, still waiting for my reference number which I have not received via sms or any other communication. The consultant I spoke to on Saturday even confirmed that my account was being charged a few times over for the same transactions. Vodacom now owes +- R3000 in over charges and I am sure tomorrow they will debit me incorrectly!!!!!