I'm going to lay out the details here because this seller is refusing to refund me my $1000+ and I don't want to be ruled against by eBay when push comes to shove.

I was searching for an iPhone 11 Pro Max on eBay. I wanted one that was new or open box and 256GB. Those were my only requirements. I found one that was being sold by a well established account for a starting bid of $1000. The auction had 6+ days left, so I think it had just been posted. I confirmed the details of the auction with the seller. He told me: "All accessories like new phone. I open for inspection and activation. Just got 2 weeks ago never use." The seller was accepting offers, so I went in and offered him the starting bid: $1000. He accepted quickly. This was 11/10, 16 days ago. I paid immediately using PayPal and was told by the seller that he would ship the phone out on either 11/14 or 11/15. He shipped it one day late, on 11/16, and it arrived on 11/18. I opened the box and inspected the phone. It had been opened previously but was definitely new. By this point, I already had my AT&T SIM card registered and activated using the iPhone IMEI BUT I was using it in my old Pixel XL. It worked fine. As I didn't have time to set up the iPhone, it sat for about a week until this past Friday, 11/22, when I decided to try and set it up. The phone had an activation lock, so I contacted the seller and he walked me through the process of unlocking and restoring it. It was HIS passcode and GMail account. The phone was able to be factory reset with no issues to speak of using the details he provided. Saturday afternoon, I decided to switch the SIM into the iPhone. The phone was indicating that I had a strong signal and I was able to send iMessages (I was connected to WiFi at my house) without any issues but SMS messages to none iPhone users wouldn't go through. Since I'm used to my Pixel which ONLY sends SMS, it took me a while to realize that there had to be something wrong with the phone's ability to connect to AT&T's network. When I did, I sent the seller a message: "This phone was brand new when you sent it to me, correct? I've already had to do three factory resets (this was due to problems with iMessage and transferring data from my old phone). I'm not able to send or receive messages on it. Honestly, I had less problems with my three year old phone. And I'm not tech impaired." The seller quickly responded: "It is brand new and still have warranty on it. You can check on the general settings. I would advise you to go to the nearest Apple store. They can help you on your issues and on how to use this new iPhone pro max correctly." I still suspected the main issue to be the SIM card, so I tried to make a phone call. When I did, I was met with an automatic message: "This phone has been blocked from use on the network." I was reasonably certain at the time that wireless carriers only block phones when they're reported as stolen but to be sure, I went to the AT&T corporate store by me. I explained the situation to them and they confirmed after checking the IMEI that the phone was blacklisted and was reported as stolen as of 11/15, one day before it was shipped. I initiated a return with the seller (who specified that he did not accept returns) and he offered me a partial refund of $850. I rejected that immediately as I paid over $1000 for the phone. I messaged him to inform him that the phone was blacklisted and had been reported as stolen. He responded: "Send me proof the phone is blacklisted from ATT if you need full refund. The condition of the phone should be like new without missing anything" and then followed up with "Refund will not be given if no proof the phone esn is bad and cannot be use with att." The problem is that AT&T does not willingly give out this information, a fact I'm sure he knows. I called the tech support line and they told me to go to one of their retailers. I went into two separate authorized resellers and they said only a corporate store MIGHT be able to help me.

Sorry for the lengthy post. These are the facts of what happened. eBay is going to step in on 11/30 to mediate. I cannot afford to lose $1000+. I need to get my money back. Does he really have recourse if I can't provide bona fide proof, other than my word, that the phone is blacklisted? What reason would I have to go through all this trouble to get my money back for something I got an excellent deal on IF it was legit?

Please help. I think I hit on every detail but if not, let me know.