I got scammed

I was trading with someone who offered me a gmax lapras for a zekrom which I thought was a steal but he didn’t have 1 million stardust so we had to do something else. We eventually settled on dmax rillaboom for gmax lapras but after we traded, I realized that it was a normal lapras. He also blocked me immediately after the trade. I spent one of my best dynamax Pokémon and 20k stardust which I won’t be able to get back but I hope some justice will come to the other player. His user was madden4023 or PoGo and here’s the proof.