Gaz is right, owning your own business is a difficult task and it does look like people like to bash and pump up their favorite dive shop. I've traveled a lot and once stayed at the #1 hotel in all of Toronto and in Mexico City (D.F.) for holiday. These hotels were excellent, "perfect" as can be, but I still found flaws, minor, but flaws. To say Amigos was a perfect 10 in everything I find hard to belive. When I come back in September, maybe I will do one dive with them and see their operation, but I am sure I can find a flaw in it, as that's why I do for a living, find flaws and help engineering correct them.
As for Peter not knowing about the problem, unless the owner is there 24/7, it is impossible to know every minute detail of what happens. As an owner, there are more responsibilites than just being a face in the front office (or dive shop). There are bills, procurments, paperwork, capital budgeting and many other tasks that need to be performed. Obviously the girl you delt with who treated you poorly won't go to Peter and say "I treated this customer poorly so he isn't happy with us", she's going to try to hide this mistake. In the end, Peter has rectified the problem by refunding the money and letting the front desk girl go. All-in-all, your diving experiences were fun and safe, that's the most important. I've heard stories about some dive operations that make you wonder how they are still in business. I can only state my experience which was an A grade, and others on here have rated ProTech the same. Go by the majority of ratings and what people say, not some hyped up "Dive Amigos, they are the best in the world" postings. In the past couple months, a few dive magazines have mentioned Belize and not one of them mentioned Amigos, the Ultimate Dive Shop in the World. We're all adults and make out own choices, but my philosophy is, always try a 2nd time. If the 2nd time is as bad or worse than the 1st, then never go back. Every chef (in this case front desk) has their off days, so let statistics play it's course.
And to answer the question about Nitrox, I believe ProTech sells to other dive shops, as I saw people wheeling empty 80's in a pull cart back to ProTech, making me belive ProTech supplies Nitrox to all the other dive shops. That's another thing, if the other dive shops didn't trust ProTech, they would not buy Nitrox off of them, they would invest their own money into the machinery, but since he is a quality shop, they feel safe purchasing the Nitrox from him rather than investing the capital into their own Nitrox machinery.