Permission not granted for the 25th

I am highly disappointed and annoyed by the service I received from Virgin active. I made arrangements with them to debit my account on the last day of every month as I am only paid on the last day but they have taken it upon themselves to debit my account today for an amount of R873.00 . This is unacceptable , if nothing is done about rectifying this problem I will cancel my contract and will no longer be dealing with Virgin active .