Abnormal factory reset

I just purchased a s5 off craigslist for 350. Thought I did my homework and called Verizon to verify it wasn't lost of stolen. All checked out fine. So went ahead and purchased the phone, bought a sim card and called and activated it through Verizon. That all went find. But during setup of phone I get the abnormal factory reset screen. So I called Verizon, they told me to call Samsung, as I did. They told me to call back with my carrier on the line, again did so. At this point, both told me there's nothing they can do for me. That I needed to contact previous owner, so I did so. I said either give me the info or money back, they quickly said they would give my money back, (great!) we set a time up to meet and they never showed later that night they text me n said they have the info to call them. I did so but she said let me text it to you. Well that was yesterday morning, I've made several contacts to them with no response. So I went to the Web and also went to my brothers (which he is a developer, not a phone developer but he is much more knowledgeable than me). We looked for back doors, but all seem to be patched. I also recreated a Samsung account registering the phone to it, doing a factory reset, still nothing. Tried to flash it to a older version (4.4.4 & 4.4.2). But Odin couldn't get it to pass. I've tried calling the phone & text as its active but nothing shows up. I tried connecting ear phones to it and making the music screen come up, again nothing. I'm out of ideas and out of 350 at this post. :( hard lesson learned here about buying phones on Craigslist. But I figured I'd post this on here to see if anyone has any other ideas