Not sure this is something the Ambassaodr team would be able to help with for several years, back in the early days of the scheme withing SPG they would be able to no issue at all but once it went official even withing SPG would be less likely. What would have happened would be if you had a hotel booked within SPG they would contact the concierge locally of the hotel your booked into and ask them to get you a prace and thus tickets for it and to be fair I assume you have a reservation for a Marriott property in Dubai and is very dissapointing they could not reach out to that concierge to arrange. Disappointing to say the least, but hey this is Marriott remember!