As I said, I have been through this exact situation with Affirm, and I did get my money back, so I know it is possible. I know others (the merchant I bought from went bankrupt) who did not get their money back- both who used Affirm and who used other mechanisms.
So I'm not saying whether or not OP would have gotten their money back had they went directly to Affirm- just that they should have given Affirm the chance. And none of this excuses Affirms allegedly bad customer service in this situation.