BAD SERVICE - REALLY BAD

I have a few contracts with Vodacom. Recently someone from Vodacom contacted me explaining they want to reward me for the way i conducted my account. I told them that i do not wish to extend any contract not do i want to pay anything extra on any contract. I now discovered that this person went ahead and upgraded my contracts without my consent. I have been calling Vodacom to query this and have had no success. This is pathetic service.