Early debiting from bank account

This is the 2nd time in 3months whereby Miway went into my bank account without authority and debited it before payment is due date. Surely this is ********* business pactice since they had nil authority to do so, especially since they did not even confirm my pay date. How many other customers is this happening to. In May my payday was on a Monday and they took the money on a Saturday. This month my payday was on Saturday and they went in on Friday. Well, they leave me with no option but to find insurance for four cars and household elsewhere.