Got mine from FT about a month ago and had the same problem with the threads. Contacted FT last night and they have offered to send me a new one once they receive mine at a processing center in Miami. Even offered to cover my shipping it there (probably in store credit).
Yours is probably under warranty if you got it less than 6 months ago. If longer, it wouldn't hurt to at least ask and see what they say. I've been happy with my Vamo, besides the threading issue. I'll be ordering a 510 adapter for the new one so this won't become an issue again.