NSFA failing to honour our agreement

I'm very disappointed at the manner at which NSFAS handles its debt collection process. I had an existing debit order arrangement with NSFAS since 2016 where on the 26th of every month they were collecting their money until they decided to stop debiting my account as from May this year without consulting me regarding this termination of agreement. Now i'm being harrassed by MBD attornies because NSFAS decided to hand over the account without informing me of the cancellation of our agreement. Now they are demanding i have to settle the full amount. I've sent several emails to NSFAS but I've never had a single response back from them. utterly disgusted by this matter. Each time they dishouner their side of the agreement I must be the one to suffer?