Contract cancellation

They are horrible, they never informed me bout contract cncellation fee and debited this amount 2 months later. When I called to get the money back they blamed it on me saying I used their data a month later. I already switched to vodacom and the sim was not even in the router, how could I have used any data? When I asked about cancellation they just informed I should make a payment and will be cancelled, yhey never informed me about anything about a cancellation fee. They drop the phone while you on the line and their feedback sucks. They just want money and will debit when they want to