I'll admit them saying there isn't anything they can do isn't right.
But like you said it keeps popping up all the time, which mean a bunch of people likely keep setting them up. Faster than techs can remove them.
I also looked up that listing and I don't see any suspicious postings at this time.
That replace # with @ thing you mentioned was likely a trick to try and sneak around the already implemented anti Spam system.
I just did a random check and found a thing like this in a minute. The guys of Amazon are aware of it. When you are too lazy or to greedy to put some tech guys or AI, or you deliberately make it extremely difficult for customers to report these kind of things, then you are facilitating these kind of scams which makes them scammers too. They should have a clear policy where anybody can easily signal if there is something not OK with a seller. But they don't, because I see it now going on for years. And if I can see it, they can see it too.