Someone dropped the ball at FNB

Someone dropped the ball at FNB's Debt Review department. At the start of the year, I made a payment arrangement with my debt counseling firm due to unforeseen circumstances. FNB accepted this arrangement and I made the necessary payments. FNB continued receiving payments from me via my debt counselors and I am now in a position to settle my outstanding debt. But when I enquired, I was informed that my account is no longer under debt review, but with collections. My debt counselors followed up and it appears someone at FNB moved my account to collections, even after the once-off payment arrangement was accepted. Until I enquired about settling my outstanding debt (which took FNB 20 days to respond to), now they have woken up and I'm getting called by HP Attorneys, all because I just want to settle my debt. All I want is a settlement letter in order to pay what is owed, but now FNB is making it way too complicated. Once this account is settled, I will be glad to be rid of FNB and I'm sure they will be glad to be rid of me.