Almost Free coffee, CVS prescription kickback and honesty

With my husbands job we are offered prescription coverage through caremark, owned by CVS (or vice versa)   For every 10 scripts we fill, we receive a $5 reward.  Even if the scripts are free to us!  This past Tuesday I received notification that we had one of those rewards.  Since they do expire and I had to check on some other things I figured I would run in.  DD coffee was on sale for $5.99.  

But when I went to cash out, the $5 was not on my card.  The cashier told me I had to send it to the card, I showed him the email and he agreed with me it was odd, but there was no way to do so.  He kindly offered to push it through for me.  Which I thought was a very nice thing to do. 

As we all know, you get an arms length (or longer) CVS receipt.  I locked myself into car and started reviewing the receipt.  THERE, for the first time was the $5 reward.  So, I tore it off and ran back into the store to give it to the cashier.  He couldn't believe I would do that.  Even commented to the next person in line about my honesty.  

Hey, I believe in Karma.