This anntagonistic attitude of yours isn’t helping any. Nobody here is saying what this guy did was right. They are, however, offering alternative reasons why things might have gone down like they did other than your assumption that he’s a double dealing scumbag. Being angry at this seller is all well and good; taking your anger out on people trying to help calm the situation by offering different points of view is counterproductive.
As for the feedback, forum rules state you can only leave it when a transaction is completed - i.e., once payment is made. If you’re not happy with how things transpired ‘in between’, then you have the option to come here and inform people about what you consider to be the other party’s unacceptable behavior. That’s your recourse, it’s done, it’s been noted, now it’s up to everyone else to decide for themselves if they’ll ever do business with this guy. I’m not sure what else you want here.