I am not sure if this is a simiar issue, but I stayed recently at the Atlanta Marriott Marquis for 4 nights. Thursday on a Cat 1-4 cert; Friday and Saturday on an EEO/BOGO; and Sunday on another Cat 1-4 cert. Made the reservation through Marriott Plat desk and while checking in, could see the confusion on agent's face. Explained the details at check-in and had them put notes on my file to make sure that I would not have to go through the entire explanation during check-out. While checking-out, could see the confusion on the agent's face so explained again and I was charged just for one night as per my reservation..
Got back home to find out that instead of taking TWO cat 1-4 certs from my account, THREE had been taken. Called the PLAT desk, they agreed with me, they called the hotel while I was on hold and put one cert. back in my account which I verified while on the phone with the agent.
Next day, I went to check to ensure that my stay at the hotel had been posted and guess what, the cert. which had been put back, went missing again. Called the Plat desk again and did manage to speak to the same agent as the previous day and she could not see why the hotel took another cert. but went ahead and issued me a new cert. so now all is back in order..
I did not know that bonus bucks and EEO can not be used back to back, so it is good to know. Is it the same for Cert. and EEO back to back?