Misrepresentation of sales information

A sales representative called me to let me know about my Telkom contract that is coming to an end and asked if I would like to upgrade. I signed up for a sim card upgrade instead of a device upgrade. The sales representative assured me that my current instalment automatically falls off if I sign up for their upgrade deal. we agreed and it was indeed signed up. Later at the end of the month, they debited the same amount we agreed that they will not debit. I then lodged a complaint with them and asked for the recording of the call. I received the recording and was in contact with a guy called Randell, not sure if he a manager or what. When discussing the call with Randell, he spoke the exact opposite of what the sales person said to me, he advised that there is no way for a premium to fall off, it doesn't make sense, even though the recording clearly states that it falls off and they will start to debit at the end of February. I then asked Randell to cancel my contract since I was misrepresented with false information. He showed no sign of remorse whatsoever, and instead made it seem as if I do not understand myself. I highly disappointed and want a refund for the money they debited onto my account. The sold false information to me, I wonder how many customers fell into their trap.