Billing Matter!!

I cancelled my insurance on Friday the 31 Aug, the consultant made confirmed that my debit order would not go through as I did cancel my insurance, now when I was with Discovery and the 1st would be over the weekend I would get debited on the Monday, now that I canceled I got debited on the Sunday, and I was not expecting it, now they tell me that I have to wait 10 days for my refund, this is not acceptable. Very unhappy