Double debit situation

They called me and asked me when I'm getting paid in Dec I said the 15th and they must deduct then. They didn't do that then I had to call them back to arrange for them to take the money. They deducted on the 19th and then deducted again today. I called and Get told it's my fault that I arranged for an early debit and that I app**** for payment assistance same time. Haibo how? Why do you offer services you can't keep up with? Tomorrow is Xmas and they double debit R2638 and now they tell me it's either I wait for 3-5days to get refunded or I have to reverse it with my bank. Imagine the que and the bank today. That money was actually supposed to be a debit order for my medical aid. This is very unacceptable and disappointing considering I have been a customer for so long.