African Bank cannot count

I have been with African Bank for quite a while now and am a good honest citizen, earning a proper salary - wanting a loan for my relocation. Unfortunately this is also the third time I have app**** and were declined. Now this last time (today) my salary slip cause the decision. My workplace accidentally paid me wrongly in July, after which I immediately paid them back. Now for a correct on their books that amount had to be corrected on my August payslip - which I understand. Now this correct is showing ''cancel net pay''. Now somebody at African Bank head office cannot understand this and cannot do calculations as they do not even look at the net pay on the rig hand side - they only see ''cancel net pay'' which means I do not really get this salary. So - I went to our HR people asking for a new payslip but as it is SAP generated she did a letter for me on a letterhead explaining that they must not look at this amount as it was done in error and it is just displayed to correct their books. I do not kid you - not even this will suffice for consideration of a loan. I have never seen such unprofessional, stupid argument, and not even wanting to re-look the application.