MBD Credit solutions

Hi I have a FNB loan I took as a Student which I failed to Pay until the end. It was Later Handed over to MBD, I have Managed to Pay the Loan but I'm struggling to get my FNB accounts closed and Get a Paid up letter. Evrytime I call them They just say we will request the paid up letter For you just give us your email adress. This Letters has been Requested for about 5 times but I haven't received them. When I check my Clearscore app or Try to apply for Credit, I don't get approval because it seems like I haven't Settled the loans. I Call MBD everyday at this Point, They just tell me we can See you Made a Payment from our side , we will close your Accounts and send you your letters but they don't. when I paid I was promised that it was only going to take 7-14 days, But it's been more than A Month now.