EBay Case Closed, Seller Wants Item Shipped back?

I recently bought an iPhone 4S and the phone wasn't described correctly. Opened an eBay case, the seller sent me a refund and the case closed. Now I got a message from the seller asking for me to ship the item to him, even after he sent me a refund, without stating a return address or paying for return shipping (after we agreed to, he still didn't).So what should I do? (As right now I don't think I'm obligated to send it back to him, since he closed the case and I never received a message in the case, where you normally have to send tracking number to return the item like other ebay cases)

Added (1). I'm sorry if I wasn't clear, I was more of not being sure if I should ship the phone back or not. Because in the case he never posted anything relating to the return address and didn't send the return shipping money (don't go saying "Well its the buyers duty" obviously you didn't read the whole thing as it was agreed to).So in other words, Why didn't he just do a standard procedure of me returning the phone then refund?

Am I the only loser rocking an iPhone 4 in 2013?

Everyone has newer phones. I had a Nexus 4 on Tmobile but the screen cracked after a month with the phone and I had to pay a $150 deductible to get it fixed. I said to hell with that and went back to my old iPhone 4 that was on AT&T but I unlocked since I was out of contract. I'm holding out for the next iPhone or the S4, whichever is a better buy. Since I have T mobile, if I upgrade my phone with them how will that process go? Or should I switch back to AT&T? They have the draconian 2 year contract but they have better signal. And no, even though I have the option on Tmobile to upgrade every 6months via the JUMP program, I can't afford a new phone every 6 months. I would want a new phone every 1-2 years. So where should my mobile dollars be spent? And do you have an old phone now? Can't imagine anyone with iPhone 3GS or older.iOS 7 will not work with hardware older than iPhone 4. And all the features will be present on the iPhone 4S and later. On Samsung side, the S3 is still awesome! And the S2 can be had for $1 on contract. And even though those phones are old, they still perform up to snuff.

Are the iPhone bumpers protective?

I just wanna know. Because I'm thinking about getting one, but before I buy it I want to know that it'll do me some good. I also heard that its expensive.

Activate factory unlocked iphone 4?

I just recently bought an iPhone 4 that is factory unlocked and now I have to activate it. Can you guys give me step to step details on how I should do this? I tried restoring the phone and setting up it, but every time I put in my t-mobile sim card, I always get a No Service notifcation. Do I restore it with the att sim card OR t-mobile?