Vodacom you make promises which you have no intention of keeping

I cancelled my contract 3 months ago, the call centre agent sweet talked me into extending my contract. She could not even do a basic thing like put my correct surname on the acc. I asked them to phone before they delivered the new phone, they didn't. Apparently the phone was sent back & I cancelled the contract. They have a nerve, they are charging me for the phone. I would rate Vodacom as one of the worst companies to deal with.