Telkom Over Billing

I have been billed by Telkom in April R195, and now I am getting an invoice for May for R459 under the name "Events Billing", I went to the store to inquire but I was told to contact the billing department now the billing department told me that I have subscribed to something which I also didn't know what that something is, that's why I am in the store to enquire about it. I am not getting joy from Telkom in helping me canceling this subscriptions, I've been to the store twice already and still no help, Now I think cancelling the contract I have with them will help with this additional charges because I cant be paying for something i did not subscribed to.