Vodacom extending contract without my authorization.

Received a call from one of the customer care agent in regards to changing ma plan not extend my contract.all I asked for was to change my plan from receiving air time to data but to my surprise my profile was updated with incorrect discussion.I don't understand why someone would call you for this but update something you never even spoke about. My came and the debit made me go crazy because how would a company debit an amount of money we didn't agree upon, how is it my fault that Vodacom is hiring ****** and people who wants to get paid by doing wrong things to customers.