Rincon has a trick with their "cash back" because it is really "bounce back." You have to return to the casino the following month to collect. And to collect you have to go to a slot or VP machine, insert your card, and enter the "redemption code."
This entices you to start playing the money when you can actually hit "cash out" and take your ticket to the nearest redemption machine or the cage.
The "bounce back" money redemption codes are usually sent at the same time as "free play codes" are sent out, and Im sure management is hoping you will play the money instead of putting it in your pocket.
Back in the good old days it was true cash back, when at the end of a trip or stay you would simply "cash out" and get your money. Now if you don't "bounce back" within 30 days its lost.