Unauthorized debits

I had a 2yr contract with telkom on one data plan. At the end of that plan I was told to contact them for an upgrade which I did. Upon calling the consultant told me that I can't upgrade and that I should take up a new plan and that he would cancel my old plan. To my surprise the next month I got double debits. This was unprofessional so I called to cancel everything. The advisor on the phone said both contracts have been cancelled. Over a year later I get debited over R2500 for cancelled contracts. I want my money back. I curse the day I ever called them. They are a ****. All of them including their employees bull**** service pretending to have retained a client all the while *****ing my money