I might be reading this wrong, but I understood that there were no refunds from the djm 92 (or Or apt model). What I understood by the staged payments is that you were paying for the development of the model - Cad, tooling, etc. Your final payment got you the model. Its hazy to say the least. In contrast to the other guys who say to put down a deposit and pay the rest when it's done. I can understand the latter modus operandi a lot better.
The second payments for djm 92 are due soon, possibly, maybe - it'll be interesting to see what happens.
Going forward, I hope Dave learns from this and makes paying for his next model a dammed site clearer