Esther, May I suggest 2 possibilities.

1. The account was transferred from another Harrah’s location (Example, I transferred my Kansas City account to Las Vegas so I have a Rio card and a Las Vegas Harrah’s card with a 121 number on it!)

2. Could the card be from another casino (possibly from St Louis) that has a loss limit. In the state of Missouri, your slot club card is used to track your loss limit (the amount of money ($500) you can buy chips/tokens to play with every 2 hours)

I hope this helps.

Ron.