Finance department messing up my bank account

I changed from compact to compact plus in Oct... Prior to that change i noticed that the bill was showing R1038, called in and was told it was captured in error and will be rectified before the debit order. This was done and R519 was billed. November a debit order of R1038 went off i called and was told it was an error but i won't have to pay in December told the lady that's not what i want i want my money back was told the finance department will investigate and return in 14 days told the lady i won't wait till then so i asked my bank to return the debit order and i manually paid Multichoice via eft. Thereafter the app shows that for December money due is R986 something cause i paid more than R519 now in November as i paid R570 something. I honestly can't keep reversing your debit order so please get your act together and rectify this if you can't then please cancel a debit order. I've called more than 5times to get this corrected from the 21st til today but nothing is being done. Please get it right cancel the debit order.