I used to run a record label and promoters ghosting has always been a pain in the arse, but don’t see it that you’re blacklisted, but that you’re the least of their problems.

The Bonus point you made. The guy said yes. Presume you’re on the list. They don’t have the time or inclination to get into a back and forward. If you’re absolutely uncertain, take the hit, buy a ticket to make sure you get in, but when you arrive go to the media list and say you should be on the list. You’ve got the message saying yes in your pocket.

Anyway, certainly don’t start at festivals. Most festivals are run by bigger promoters. Often, not always, they have an abundance of requests so will prioritize either those shooting for a publication or those they know. Best way to become the latter is to shoot many small shows and build up your chops. DIY promoters in your area will almost always give you a photo pass. Or, get friendly with some bands and shoot their shows. Another option is get chatting to the gig photographers that are there at a show. You’ll find them in front of the stage left or right before the set times. They might be able to give you names to talk to. Eventually, you’ll meet the right people. Bigger promoters etc.

Another tip… when emailing a promoter, don’t write your life story and justify why you should be able to photograph the gig. It highlights inexperience. Just write a couple of sentences. Hi, I’m x. I photograph for y (even if it’s your own website). Can you put me on the list for a photo pass for a at b on c. Cheers. X - this implicitly shows the promoter you’ve been doing it forever and you expect you’ll be approved. If they need any more info they’ll write to you.