Pension backed home loan ****

I app**** for a pension backed home loan with Standard bank during 2018. I receive quarterly statements reflecting the outstanding balance and on the same month when I received my statement, my pension fund settled the loan. However Standard bank increased the balance by over R5000.00, than that of the outstanding balance - when I enquired no one at standard bank can explain it and I am sent from pillar to post. The number for the pension back department no longer exist and I am left in limbo because no one can see the account on the system and emails go unanswered. I am not sure why Standard bank is so secretive when it comes to the dealings of this department.