MFC dissapointing service

Im Very dissapointed with how Mfc have been towards handling my account ***1, i did settle my account and i sent them proof of settlement payment, 3 days later they deduct R4106. 58 on top of that Tumelo maja sent me a letter of demand, for what, im still puzzled. Whereas Mfc is the one owning me R4106. 58, they need to refund me and stop sending letter of demand. I regret doing business with them