Unhappy about a cancelled data contract

I had a data contract which expired last year. It kept on deducting up until I went to cancel in May. The company kept on deducting still and I kept on reversing the amount and blocked the debit order. Yesterday they deducted triple the amount on my account and I dont know why. I went to Telkom and was told that they are changing me for the reversal. I am so angry with the treatment I received from them and feel that they have taken an advantage of me.