UNABLE TO EXPLAIN HOME LOAN AMOUNT

AFTER AN HOUR ON THE PHONE I WAS GIVEN THIS E MAIL ADDRESS ********** AND ********** BOTH OF THESE MAILS REJECTED BACK TO ME. THIS IS THE MAIL I SENT TO HOMELOANS: I'm in the process of moving banks over from Absa to Standard bank. My normal home loan amount is R6 038.56, on Dec 30th 2017 I was still busy moving funds over, you took your debit order and it rejected as there was not funds at the new account at the time. I did deposit money in the account that reflected later that day, i called your call center to tell them to rerun the debit order. You guys ran then an amount of R10 148.97, the also rejected as i only allocate R7000 a month to Nedbank to take from my account. When i called the call centre i was told this R4000 extra was outstanding from 12 months ago when i started the home loan. Please can you give me more details on this R4000 that has now come into affect?