So I called to make a reservation using the Amex Weekend night certificate. The agent saw my cert. in my account, proceed to book my stay. Then he claimed he had trouble saving the booking. Put me on hold for good 10 minutes. Then came back on phone asked me whether I made a booking while on hold. I told him no. (One can never use the certificate to book online, as far as I know.) Then he sad my certificate disappeared from my account and he didn't know what happened and where it went.
Since the certificate was lost from my account, he could not make a booking for me, despite I have my certificate reward ID email.

He opened a case for this and said I will get a response via email in 24 hours.

Have this happened to anyone here? Will I ever get my certificate back? Not getting my hope up!