Extremely annoyed

I am extremely disappointed with FNB connect, I called to cancel my data bundle deal with them, i was told because they had already debited I can only cancel the following month, I did exactly that, my data for 2 months was never loaded on my Sim even though they would debit my account. I am extremely annoyed, my contract is cancelled, they continue to debit my account yet they don't credit my account, what kind of incompetence is that.