Well basically they did provide you with the service but fucked up by using some of your crafting materials? 1500 ad and 500 vc is not much at all tbh. And why i can't see anything about that Akkan's chest piece in the chat?
When paying for shady online services that have absolutely no guarantee to provide you with anything at all, you are taking a risk. But this does not look like a scam to me to be honest because they did not strip all of your characters from their gear or something... Or maybe your gear is so crappy that the only thing they took was crafting materials and an alleged Akkan chest?
Besides, how the fuck did you get to the conclusion that hiring their service is a good idea? They charge hundreds of dollars for basically anything.
1) Edited the title. We instantly delete all the spam from this service as it's the most illegal thing you can do in D3 and absolutely against the ToS. Therefore, by mentioning their name in the thread's title, it's giving them more publicity than it should. I hope you understand.
2) I'd say you learned your lesson, so I'm not sure why you'd trust them your account again. As Jamoose said, this is an illegal service and the only reason they're not responding with "LOL, your fault for trusting us" is because they want you to pay more money for their "service".
3) As I've said, I don't feel good about this thread. But maybe this can serve as a warning for everyone who even remotely considers that this is a good idea. This is highly illegal and, as everyone should learn from OPs story, absolutely not worth it. I also wouldn't be surprised if Blizzard at some point bans all accounts who have been accessed by this "service". Stay tuned for the next banwave.
How can they plunder anything when everything is BOA? Or provide them for that matter? (Other than by grinding your account.) I've heard that they can trade you massive amounts of dyes to vendor to sell you gold, but how can they deliver anything other than crap legacy gear?
Honestly I would guess they were just screwing around and dropped the Akhans piece on the ground, maybe a casualty of some screw up multi boxing. And whats your guess as to where the mats went? They produced a bunch of yellows for their farmer / scammer army?
All in all, sorry you got burned, but....yeah you took a huge risk for very little gain, and in the process financially supported some pretty shady cats.