Extremely bad service

I purchased two pairs of shoes for my dad and mom online from Hush puppies and the other pair didn't fit my mom unfortunately and I had to return them firstly they **** and said there was a gum stuck underneath and to cut the long story short they agreed to process the refund they asked for my banking details I gave them the correct details for the second time they asked for the banking details and I gave them the incorrect banking details how? I don't know how that happened, I called them to ask as to when was I getting the refund as 10 days has passed according to their refund policy and they advised me that they processed the refund already they sent me proof of payment and the banking details were wrong I called my bank Fnb and they advised me that Hush Puppies must log a query for missing payment with their bank Nedbank and they are refusing to do that they telling me they cannot log a query as I'm the one who gave them the wrong details, this is my money we talking about mistakes happen everywhere I opened a Capitec account this year and immediately somebody deposited R5000 into my account by error Capitec called me and asked me to give consent to reverse the money and I told them that I'm aware of that transaction and yes at the end of the day it's not my money they must give it to the other person cause it is rightfully hers and I incurred bank charges but I never disputed that I just told myself that is one of those things, so Hush Puppies tells me it's done I forfeit my money just like that we talking about big institutions here( Nedbank and Fnb) and both banks are saying it's possible for me to get my money bank or else go to Saps to open a case