Xbox Will Not Honor 1 Year Warranty

I spent over an hour on the phone with xbox tech support yesterday and narrowed down my issue to a bad wireless card. However, because I bought the system at Costco they will not honor the warranty. I was told they do not have a relationship with Costco.
I am supposed to know that as a consumer? I bought the system in 7/2019. The supervisor escalated my complaint to Microsoft Corporate but wasn't too promising.

How can Xbox not honor my 1 year warranty when the system was bought new at a major retail outlet. I have the receipt.

:)