Vodacom cancelled acct and false sales pitch

Very disappointed. I received a call from a sales agent selling me a new renewal contract. I advised I was not interested. She advised they would add a new sim to my acct. I advised again I did not want a new sim. The lady said I needed a new sim for the data to be added to the acct. The lady did not tell me I was getting a whole new sim number. On receipt of the sim I tested it and it was a new number that could not receive calls. I immediately phoned and told Vodacoms agent Thabo to cancel the contract. Guess what, it was not. Thanks Thabo. You do Vodacom proud. Now I got a bill for additional R600 because Vodacom is ***********. The lady I spoke to today advised Thabo did not cancel the contract. I will never open any contracts with Vodacom if they phone me again.They clearly only care for sales. And cancellations are not processed. Bad service.