(This site is fan based. It has no actual connection to anything official.)
Well, the point of a mobile authenticator is that it's on a specific phone. So anyone logging into the account has to physically have your phone. If you're getting a new phone, you need to first remove the authenticator from the account, then set up a new one on the new phone. If you didn't do that, and don't have the old phone anymore, you're locked out of the account.
It sounds a bit annoying, but that's the trade-off for security that actually works: it's possible to lock yourself out of it.
The advice is the same, though: just wait for support. I had this issue with my Blizzard authenticator before, and they were very prompt with removing my authenticator once I was able to prove who I was. I hope Arenanet gets back to you soon.