Incorrect cancellation fee

On Feb 26 2015,I called Vodacom Customer Services to cancel my contract & requested a settlement amount.I was then given 2 amounts to pay in order to settle my contract prematurely.I asked the lady if she was absolutely sure that those were the correct amounts to pay as there was an extra amount on the settlement letter she had sent me. I paid those two amounts she had given me & I gave her the go ahead to change my account from Smart S to Prepaid. She confirmed everything however the contract wasnt cancelled. It carried on until I phoned again a month later to say my account should be on Prepaid by now. I spoke to another lady & she cancelled it immediately. Mid April I receive an invoice for usage of Data from 26 Feb to March, which I have no problem with, however, the statement reflected an outstanding amount of 2,206.46. I called to query that which was only then that I was told that I was given incorrect amounts for the settlement and my payment went into the outstanding account. Vodacom has proven to be *********** and that has led to a major inconveniece and they have a nerve to call and tell me I will get listed yet it is THEIR FAULT because I was willing to settle in Feb.