Account on hold - complainant refusing to send affidavit to lift the hold after receiving their money back.

I use my bank account for client payments and one of the clients requested a refund on a payment for an order they had made using someone else’s account & reference. While I was trying to trace that I realised that my bank account is on hold again. I then called the bank and was told it’s for K Kheswa from Capitec on 20 July 2021. Fine I call transactional ***** and they explain what should happen - I speak to the particular clients to trace how they made their payment so I can pay them via cash deposit and I do so. Now they have refused to notify Capitec that they have received their full Refund and write and affidavit saying that it was not a ********** transaction. It’s been over a month and my account is blocked with funds I need as I’m expecting a baby soon! Can Standard/Stanbic bank assist me because those idiots at transactional ***** don’t read or reply to their emails and when you call them they all give you different solutions as if they aren’t trained for the job! What must I do? The person received their money and I have messages pleading with her to send the affidavit so the bank can lift the hold and they’re ignoring them. I run an online business with clients all over SA. I wouldn’t even know where to trace this person.