Debit order

I signed up for the DSTV Explora last month. Multichoice informed me they would make a R849 debit immediately (14 Sept) and this amount would be held in \credit"for the remainder of the month - fine. I was told that I should cancel my existing debit order of R808.50 so this amount would not be debited at month end. I received the decoder and that very night (18:56 on 16 Sept) I phoned Multichoice and instructed them to cancel my debit order. After a lengthy phone call (at my expense) of 18 mins"