Disappointing Service from Vodacom Call Centre in contract cancellation

Good day Need to cancel the contract when i did an offer was given to renew the contract. I had told the sales agent, let me think about and call me on the following Monday. However i called back the next day as i found Telkom to have the same offered package at a cheaper rate. I was told by the new consultant that he cannot cancel the contract as the previous sales agent is busy with it. The Monday arrived three weeks ago, and still no feedback. Vodacom still debited my account inspite of my attempting to cancel the contract. We are the customers, we pay the account and therefore we should terminate the contract if we desire too.

Thanking you

Bhana