eBay

I try to list an item but the message says "session not found" keeps showing up when I press "LIST IT". What does that mean? How can I fix that problem?

I was fully refunded for an item that I did not receive. Then the item appeared as unpaid item. Is there any way I can change that? Do I need to notify the seller and ask them to change that? Last time I had this happened to me I have trouble paying ...