It looks like Oskar's tone might have been blunt, but his actions showed integrity. A full refund, and Retra paying for the risk of currency fluctuations seems, to me, the best resolution anyone could hope for.
I think it is unfortunate that you as customers were alienated. I know that, several times since February, I either posted here or on Retra's facebook page about updates to delivery dates, and the responses were always fast and honest and not at all hostile despite my occasional prodding..
While I wanted them earlier, I knew I was financing a start-up venture in a niche industry with a niche product. I fully expected that time frames might slip (and it seems some of the slippage was due to making some significant improvements to the flashes).
I would never have dreamed of planning an important trip or photo shoot on the arrival of these flashes. When one of my existing flashes died, I just soldiered on with one and if needed I would have bought a used replacement.
Certainly, if I were a dive professional, I would not have made services to my customers contingent on a product whose production I had no control over.
I don't see any reason from how Retra acted to doubt their customer service. Of course, I know that if a flash breaks service will be a long process (shipping to Europe and back, etc). I, like all of us early adopters, are taking the chance that the strobes will be reliable and bulletproof and not need service.