Pathetic Nedbank MFC

How is it that our contract agreement is to deduct the instalment on the 25th but MFC decides to do it on the 22nd November if it was December I would understand, I even took it upon myself to call them few weeks back to find out about this arrangement they send on messages but NO they’re clever with my money so they deducted whenever they feel like. Who is going to pay for the bank charges then as I am now in arrears??