Chase Sapphire Preferred $50 Hotel Credit was denied?

I've had this card for years, finally decided to use the $50 hotel credit benefit. I booked a hotel in January via the Chase travel portal, paid for it with my Chase Saph Preferred card. Stayed at the hotel (did not cancel the stay). The credit never appeared.

Every time I called, they said wait for the next statement. After 3 statements, they escalated it, and now I just got a letter saying the credit was denied (with no explanation why).

Anyone else encountered this? How to dispute it from here? Seems wild they will not honor this, and also not explain why.