Billed 3 times more than i normally pay

I took a Telkom SIM only package last year around Sept. When I took the contract I was told that I would pay R99 per month. That was a lie because I have never paid that amount. My debit orders differ every month. Now this January R316.94 was debited. I don't understand for what. I do not want your services and I would be visiting my bank soon.