I can hardly believe he does not reuse the mules or how he called them "nominee". We all understand this is considered money laundering in every country.
You can't use "money laundering" as an argument here. It would be as if you bought drugs and then complained how the seller is a drug dealer. Yes, he is and you used his services. You know very well what the purpose of those cards are and why they are registered in someone else's name and not yours. That's why you used them. So let's leave that aside.
I'll say it again: My personal opinion is that you won't be able to prove that you got scammed by this service. Had your money disappeared while still under warranty, it would have been a very different story.