Bad service no response

My parents bought a house for R910000.00 thousand end of 2015 paid the a lumpsum towards to loan was left owing R70000.00. My Dad passed away May 2016 and the morgage was registered on my Mothers name. We had a shortfall on the estate and wanted to apply for an accessbond or further loan for R250000.00. Was brought under our attention that the debit order was never cancelled on my dads account and was sent back as unpaid for almost 7 months. Just after my Dad passed away we went to the bank and made arrangements to pay the monthly installment monthly using EFT till the estate was finalised. (Nb we never missed a payment throughout the whole process) when we app**** for the loan we were informes the account is 7 months in arrears this being that Standard Bank provided us with the wrong account number. We submitted our bank statements to proof the installment was paid in time every month. Standard bank rectified the problem and transferred the funds from the wrong account into the correct one. After that we were still declined because of the 7 months that the account was not paid correctly every month and that we are blacklisted at Standard bank because of the 7 debit orders that was never cancelled from the bank side. After long fights it took us a year to get the loan approved due to the errors from the bank side and the loan for R250 000.00 was paid out November 2017. The property is worth R959 000. And our original loan amount was R 710000.. we app**** for another R170000.00 loan that we qualify for but at the end of the application we were informed that the application was denied due to the account and my Moms name being blacklisted as the result of the error. My mother was not at fault so why must she have a bad record now and penalised for the banks error. My number is ********** email **********