My reply :)

Hi Lauri, Thank you for bringing to my attention the fact that a player's cards belongs to the casino that issued it. I was actually aware of that fact, as most casino's in the US state pretty much the same thing on the back of their cards. For some reason, SunCruz is the only casino that has contacted me, and requested the return of their property. At the time of reading your email, I have no SunCruz player's cards in my possession. I appear to have sold them all.
Thank you for your concern,
You have a SunCruz day,
Andy