cancelling a reward

if you purchased a reward, but you cant use it, can you cancell it or exchange it prior to redemption?

if its a booked room or show then I beleave no but anything else yes. go here
https://support.myvegas.com/anonymous_requests/new

yes for most rewards go here https://support.myvegas.com/anonymous_requests/new

I have gotten buffet rewards refunded a few times. No problems

its for a buffet, thanks