Four of my SNAs was submitted by yet another sloppy Marriott agent for somebody else's reservation. Luckily I got an email and then had to spend 1h+ min on the phone ....to add insult to injury it could not be reversed immediately I had to wait to the "end of the week" ... Really sub par customer service ....
So the moral of story: "don't fret if it seems that you can't redeem your SNA anywhere .... a Marriott agent will do it for you ... for someone else's reservation "