Pathetic service and admin

Car was written off and Mercedes Benz was the one that suspended my debit orders when they received settlement quote requests from the insurance. Insurance paid their portion but MBFS flagged my name as missed payment for 4 months while the matter while being dealt with by the insurance. I've queried this with a few consultants at MBFS who have promised my ITC record would be rectified but to date it still shows missed payments. I still can't even get an updated statement from MBFS, their service is very poor and frustrating. How do I even think about buying another Merc?