Something similar happened to me, I bough a laptop that cut off after a few minutes and wouldnt hold its charge. I ended up calling and messaging the seller, but he wasnt answering , I then went back to his house, I seen him look out from behind the curtain, so I shouted up at him, he just let me in because i was making a scene , It was quite a traumatic experience, when I got to his doorway, he was very very angry and tried to get me to go into his flat, teasing the money at me( I was in the hall way of a block of flats. I kept asking for my money back, he finally had to give it to me, because of his neighbours, but then he wouldnt let me down the stairs and tried to take photos of me on his phone. I shouted out and luckly some one arrived. I was too scared to do anything about it and felt lucky that I got away safely it was many months ago and I am still shaking and this is the first time I have mentioned it ... I still see the same seller just now here on ED . maybe it was the same guy as you got the phone off, I realize now that I should report him to admin, maybe I can. :(