UPS nightmare, cancelled installment plan and trade-in charges

UPS lost my iPhone for two months and during this time I was charged monthly installments on it. Eventually, it was sent back to Apple and they refunded the order but the installment plan remains on my Apple Card account and it charged an additional $500 to my card because the trade-in was never completed...because I never got the iPhone in the first place.

Since then, I have been playing ping-pong between Apple and Goldman Sachs for over two weeks because even though the return was completed and I received my two monthly installments back onto my credit card, the installment plan for the phone is still inside the Wallet app and no one seems to know when I will get my $500 back. Apple says that it sent the money back to Goldman Sachs and gave me the invoice for the $500. They say it can take up to 10 business days between both entities to get this through but it's been much longer than that by now. Goldman Sachs says they don't see anything which is unhelpful. Every time I call Goldman they can never understand me when I'm speaking clear words to them so it's an endless loop of asking remedial questions and repeating words they don't understand. There's no email for me to use to make an inquiry and I've been transferred tens of times at this point by Apple and Goldman both on the phone and through chat.

For the last two months, I have been unable to use any of my Apple Cash that I accrued through my card purchases because this refund will result in an Apple Cash adjustment and if I move that Apple Cash and they adjust to a negative balance I could have my account closed and be banned from all Apple Pay services.

Due to a combination of UPS' incompetence, Apple's strict Apple Pay policies and Goldman Sachs glacial and inadequate customer service, I have been put in an impossible position and will stay stuck here at the mercy of a bank that I exclusively use every day and is now going to charge me interest on my balance.