Curious, could you have still helped to promote the show despite being out of town?
I'd be looking more for a booking %$ than name credit since you are not actively promoting, sponsoring, or attending the show. (Perhaps this is what they thought?)
If you have emails or even voice mails from said person, stating your expectations, that's something, albeit not a contract. But if you have not heard from them, what can you do? Not sure it's kosher to contact the talent or venue at this point. Other than maybe reach out to them for future business.
At the very least it's on your list of experience if you have the venue/talent as a reference, and documentation if anyone wants to check.