Vehicle Restructuring Finance arrangement from hell

My Vehicle restructuring with ABSA was supposed to begin on the 27th of February of which only a portion of my monthly payment is supposed to be paid for 6 months in accordance to our arrangement. However every month I have to deal with their collections department. Last month i paid the agreed amount and now I am being told my account is in arears. How when I have an arrangement with you??!! Calling the call centre is just a waste of time because all i hear is i'll escalate but the same issue keeps presenting itself every month as nobody is able to explain whats going. Like this was a very simple request. I can't keep having this issue every month till July. If there was an issue with the arrangement then they should've clarified so cause now it's messing with my credit score.