I see the error in my ways at this point, but it's after the fact. As stated previously the vouchers weren't sent by email, they were sent by eBay message where you contact the buyer about the item, it never touched an email server. I could understand the stance the item wasn't delivered if it was by email, but by contact in eBay is another story. This process is exactly how I got involved with CEX, I purchased a legitimate voucher code on eBay and got started mining, then was able to grow my GH/s through mining, and then purchasing additional equipment to mine from home. This isn't a BAD IDEA, this is a way to get more people involved who don't know how to get into mining.
As it stands now, the buyer didn't reverse the funds, the eBay account has hijacked, which is why PayPal froze the funds. I'm the one that took the risk, but it's disturbing to know that CEX refuses to cooperate in identifying the perpetrators of the fraud. They were willing to identify the user accounts, I have both of their usernames, but I have no recourse, and CEX while admitting the purchases were fraudulent refuse to do anything about it. It's like someone stealing money out of your bank account and the depositing bank refusing to release the deposit of the fraudulent funds.
I've posted this thread to be sure that others are more aware of the ways other can and will defraud you. I had expected more cooperation from CEX when they openly admitted it was fraudulent. Live and learn...
Additionally: "But I swear I sent them something via eBay message." is something that eBay can prove. it wasn't sent via email...it was in the contact service provided by eBay. How would I know that the "verified" eBay member was fraudulent?
It's not cex's job to reverse anything. They did absolutely nothing wrong. This is just like if you buy stolen merchandise. When the police come to your door to recover it, they aren't going to offer to reimburse you for it; you're out. It was a risk you took, not someone else. Nobody else can be held responsible.
And I understand your idea that it's not a "bad idea" to buy/sell online. The issue here is we're talking about eBay and PayPal. eBay and PayPal. eBay and PayPal. Seriously, do searches online and you will find thousands of horror stories from them. And everyone in this community should already know that you don't use them for anything Bitcoin related.