Vodacom what in the hairball are you doing?

I was contacted regarding a migration to another type of plan. However when the debit order was done. It costed me almost R300 more. I don't want this plan, I want to go back to my old plan. The lady spoke so fast that I couldn't tell what she was saying, as she said it's not an upgrade or change the contract. I sent numerous emails to client care but to now avail.