A similar thing happened to me, and I was lucky enough to get help from Namecheap's support (they actually escalated it fairly high in the command chain).

After that incident, I decided to move my critical email communication with just the barebones provider's domain to either Apple's iCloud (you get a free account when using iCloud) or Fastmail (paid but worth every $).

This way I don't need to worry about my own domain for critical stuff.