I've seen others have success complaining on the Coinbase subreddit [1]. It's run by Coinbase staff and they seem to respond better there than the ticketing system.
Thanks for the suggestion. I sent a direct message to coinbasesupport from that subreddit three weeks ago and never received a response - public shaming must really be the only way to get traction. Which again is completely unacceptable!
> If posting for assistance please provide your case number in your post. Moderators will only respond to PMs that have been requested in a post, and unsolicited DMs to individual moderators and chat requests will not receive a response.
Maybe if you try to create a normal post, you can get help faster.
[1] https://www.reddit.com/r/CoinBase/