They don't want us to cancel even though the contract is finished.

I don't like what Vodacom is doing, I had a cell phone contract with them via game... my contract is finished but the still deducting money and sending statements and when I try to cancel via customer care "They say I must contact the company that send me airtime" What a heck..... All of a sudden I'll be on credit bureau unnecessary. Please get your stuff right if you still wat to keep your customers.