Interesting read.
At first I thought you were blowing things out of proportion, but when you finally got a public reply from the guys at PM I was impressed. That message was outright threatening.
I'm pretty big on customer service, and find that contacting the manufacturing company with issues will usually get you the best answers. Most of the companies I have contacted with minor issues (Aqua-C, Hydor, San Fran Bay Brand, Reefcleaners, PUR, Marineland, Eheim) were all very helpful with finding solutions to my problems/concerns. In most cases they offered to send out replacement parts to help fix my issues. Mind you that none of my products were bought directly through the companies, or even purchased new. I always mention that I purchased the equip secondhand, and they are STILL willing to ship replacement parts sometimes for free, sometimes for just 5$ to cover shipping charges. The only brand who gave me bad customer service was CPR, and I don't think I'll be buying another product from them again.