Wyndham always wins. To survive with them you do have to suck it up sometimes.
They don't have to answer to anyone. They can audit, freeze, cancel reservations, whatever and whenever.
Their systems suck, as in the case Jan detailed, you could miss a payment a few months back, and have subsequent payments post so not realize you have a problem. Similarly, I've bought resale contracts more than once where the maintenance wasn't paid on the seller side. Resulted in pretty much a past due account on my side. My monthly payments continued to pay automatically, but I had an overdue amount from the transferred contract. And, yes, my account was at risk. I paid the balance and then settled with the seller. Right or wrong, my account was at risk of being frozen or having reservations cancelled.
You will never win with Wyndham by being argumentative. Be nice and you'll likely find a rep at Wyndham that will work with you.