Free Ride promotion on Booking.com not disclosing which airports clearly

I booked a room specifically because it included the "Free Ride" promotion. However, the promotion did not clearly disclose which airports were eligible before I chose the "pay now, non-refundable" option. Only after completing the booking did I see that the free ride applies to just two airports, not the one I booked my flights to. At no point during the booking process was this restriction visible. Because of this, my travel logistics flight plans, and budget were disrupted. What should I do? Has anyone dealt with this issue? And what happened?