I am not taking sides here, but I can relate, as I had an issue far worse that stretched over 8 months (a Canadian company) with no customer service or concessions by the company owner, who I talked to on the phone. At the end of 8 months, I ended up losing $5K on the deal. I said "never again"
I say VMPS or anyone else willing to "make it right" is worth the try. Even if it costs you a couple weeks time, it would still mean you are selling the speakers 100% working to a customer and you are not punishing yourself economically for something like this.
You may have hard feelings about your situation, but IMO, you only stand to gain-and recoup a LOT more of your investment if you allow the speakers to be fixed. I'd buy the RM40 for $500 in a second, if nothing else to fix them and sell them for a few grand so I could get some RM2/FST, or in your case, whatever you want to use a few grand (vs a paltry $500) for.
I can sympathize with your feelings, but also experienced far worse. I wish I had as good an offer as you are getting. I'd have my $5K back.