回複：請教關於在craiglists上賣東西的糾紛

I can share with you from my experience on eBay.

Ask the buyer to send the phone back at his own expense first. Once you received the phone you can examine it to see if it has other problems. If there's no other problem or cosmetic damage, then you can refund the buyer. You do not have to refund the shipping charge. You can also offer the buyer to send the phone back to you for repair. If the buyer does not agree on the terms then it is his problem, not yours.