How can I get a chargeback defect rate removed that’s not my fault?

I just keep getting the run around from seller support teams and account health teams.

A client set up a return, was given a label to return the item, they must’ve set this up before the item was even delivered and then we they got it they just refused the delivery.

Items don’t ship out from the same place returns go so I had absolutely no clue they returned anything until they filed the chargeback and I looked at their original tracking and saw that they refused delivery and there was a return tracking. I refunded them immediately when I saw this despite the fact that I can’t find the 80lb return.

But this BS defect, the first one of any kind I’ve ever gotten, has brought my sales to a halt. I usually sell 3-4 items a day. I’ve sold 1 item in a week. My buy box is zero. Is there nothing I can do?