Will i win this ebay dispute case?

I got a iphone on ebay, asked the seller for receipt before opening the phone as he said no returns after the phone has been opened so i just wanted to insure the phone to be on the safe side. He said no problem and he'd send it but stopped replying to my mail for about 2-3 days so i wrote to him saying i'm going to start using the phone, then when i turn the phone on it won't accept my sim, i contacted him telling him this and saying i haven't touched the other accesories like earphone usb and charger and i want a refund because i'm not paying 377 for a phone that doesn't work and seller says to me no as he stated no returns after opening, i opened a case on ebay and hes still saying no return but how was i meant to know this was going to happen and there was going to be a fault with this phone if i didn't open it? I'm left with no phone. Will i win this case? And how long does it take?

You might, especially if the cops show up at your door.

I would contact your phone company - find out why it will not accept your SIM card. There could be a number of reasons. If the reason is compatibility, you might not win. Whatever they say, you want them to email / fax (better) stating the reason. Then that will help eBay

You can if you ask and report this guy to eBay. Explain your situation and don't forget to mention that his policy was no returns after opening, but this was a faulty phone and therefore you must really push for a demand. I had the same case with a battery and they sent me another one, but that one was faulty too! It was only £2 so we left it however.