Cell C daylight *******.

I canceled my data account with Cell C after they suddenly started taking double my usual fee for monthly data. After cancelation I noticed that they took another (extra) month's subscription. I reversed the debit order and gave them a call. They then said I owed R79 (I assume it was pro-rata), which I paid immediately. The next month I receive a statement. They charged me R70 te reversing the debit order. According to the statement I DID NOT OWE the amount that I reversed, only the penalty fee. I contacted them via e-mail. The last communication was that they were still investigating. But they took the R70 from my account again. This time I left it and mailed them again (saying they're robbing me - no response as yet). BUT the new statement has ANOTHER R70 or canceling the penalty. How can they charge me R70 if taking back my own money, TWICE?? Appalling!