Excessive & incorrect billing on data usage

Firstly, i have been with Vodacom for 2-3 years and have never missed a payment. my contract which is used by my wife was declined for upgrade beginning March. My wife subsequently went and got her own contract which was received/activated on the 12th of March. so the contract/phone that was declined was off for the duration of the month from the 12th. I have been debited today 31st March R1700 and after querying the issue, was told that R1100 worth of data was used. Now after reading several other posts here i feel that my efforts in logging an investigation is futile.. Subsequent to this, i wanted to cancel my account so i called in and guess what.. i wait and wait and wait and after 45 minutes of waiting with no answer i ended the call. i want a refund on the incorrect amount debited and want a representative to contact me and my contract be terminated immediately. Vodacom is the worst SP i have ever come across.. you can kiss my business away for a lifetime, i advise anyone reading this to please realize that this will never go away and will continue to be taken for a fool an money ******!!!