I am so sorry you are dealing with this. I would be very upset if this was me going through this.
There's an Instagram account with 78.3K followers, @ramaworks
There's a Twitter account, too.
Allegedly two key people left and formed another company.
My advice: contact them through Instagram and if no response in 48 hours, dispute the $600 charge with whatever form of payment you used originally, and find another build for your bro.
Good luck.