Dispute

Since September 2015 I am not getting any accounts from Vodacom and suddenly at the end of September, my cellphone account was more than double of other months. Instead of R1 700.00, my account was R4000.00 without sending any account to me. The end of October my account was R2060.66 and again NO account. We requested the accounts from Vodacom without any success. If they've got nothing to hide, why not sending as an account with itemised billing which we pay for, so that we can see where the problem is. The service at Vodacom is absolutely pathetic, because as they promise, they don't get back to us regarding the dispute which we put in, and also which they promised by sms they will do. Vodacom is getting from bad to worse and the cellphone cost just keep on increasing. How do I go to get an account?