If his feedback checks out, send him some more messages and he will get back to you.
I tend to wait the 14 days eBay states is mandatory beforing filing a grievance. Just wait 2 weeks if he doesnt get back to you then contact eBay about it. I’ve done that numerous times. Don’t just leave bad feedback because he didnt get ahold of you asap (despite his ad saying it will be void within 3 days if you didnt)
I usually give people the time to get ahold of me unless they signed up 2 minutes prior to the auction end and buy my item. Those asshats get the immediate dismissal. Rar!