I didn't know there had been a change of management.
It's been a while (I think 2013), they were bought by the world's largest radio advertising solution company Ando Media who did exactly nothing with this new asset in their portfolio other than discontinue any ad insertion software and features SAM has had before. I've got no idea if SAM was really such a major competition to them or if they originally had different plans, but I can see so many options to benefit from each other just from the outside and they did absolutely nothing in that regard.
On the contrary, they let go of the founders of the company and slowly but steadily all people from the support, sales and technical team that have at least sometimes interacted with the community before.
I only started being really active in the forums about a year or two before the company was sold, but before that time you could easily get someone with deeper technical knowledge either on the forums or via support tickets. These days it's looking more like noone over there is aware of all the features or has even used SAM themselves before.
So I want further explanations from the support: Why did they tell me that the problem was definitely the DB?
Probably because you already narrowed it down to the DB and they just took over from there without considering alternative solutions.
That happens to the best and there's nothing you can do about it. I think they should've tried to diagnose the actual problem with the database, though, and not just wave the problem away, but that's just my personal opinion.
Meantime I start to prepare my article for TrustPilot and request a refund from PayPal. Then maybe they'll surprise me with a detailed report...but I don't think so.
I wish you luck, but I don't think your chances are high.
They delivered the license key and the activation is working on a fresh install. Even more so if you use the known-good-configuration (i.e. embedded Firebird Database).
As far as I know, that's enough for them to fullfill the requirements of the PayPal buyer/merchant protection warranty.
As for review sites: I sincerely doubt they care much about that. There's just very little competition in this market and the market itself is relatively small, I guess they don't get many users coming in from a rating site or even looking at one first.
That doesn't mean you shouldn't try that and shouldn't write down your experience. From what you reported here their support was awful and left you on your own to figure out what the actual problem was. That's pretty much the opposite of what a dedicated support team is there for. But I've heard many reports very similar to this one before and therefore am pessimistic about changing this in the future.