There are a big possibilities that Ebay fraudulent activities group of seller team together to prevent others seller from selling. Let say I have an item for sale at $20 a piece, then another person list after me or before me listed for $25 a piece, just a $5 different, but these greedy nasty mind sellers whom selling higher know that they cannot sell it quick as me, so what they do is ask someone from their team with different ebay seller or user name and purchase my item without making a payment, and sends a message to me saying, they have problem buying or entering the address or payment was not accepted and so on, so what this does is making your item went offline from ebay in limbo you’re not getting pay and you’re not shipping it, making the higher cost item $25 now appear on the list 1st as cheapest when people search on ebay for the same item, basically they try to cheat and selling it faster and profit more playing this game. What can you do about it? simple:

1. Ensure to indicate immediate payment required
2. If user don’t pay, immediately report or open case to ebay saying payment have not receive and cancel transaction
3. Re-list your item

ebay buyer purchase but didn’t pay jus to put your items offline so others can sell their items at higher price ensure to have required immediate payment