Debit orders when ever suite them, not contractual!

Since the uptake of our policy, we on more than one occassion was debited when ever MiWay feels like debiting us. The contract states the 8th of each month. How is it TCF to just go and debit a persons’ account wheneved you feel like it? There has never been a missed payment, never a claim, but this is how you treat a client when since inception, the contract was done with a debit order date if the 8th and all this for a reason. I will be loading a TCF complaint, because I now more than had enough.