Sifiso khawula

I have an agreement with netbank MFC Deparment to deduct my car finance every month the amount of R4783 but the division always Deduct only R4000 and I called in to ask why are they not debiting the full amount no1 has answers for me not ds thing is putting me on debts cz now I’m owing the amount that it could have been avoided and my question is why is netbank not debiting the full amount are they trying to put me on Debts. It’s 2months now in a raw they doing the same thing