What do I do when a seller's return address is incorrect and they won't return my messages

[ruby*tuesday]

Have you opened an EBay Returns Case in the Resolution Centre?  You have 30 days from Delivery. You then use the Label he has to generate through the Case which has a Tracking Number linked to Ebay. They check the Tracking to Confirm Delivery and will Refund you as long as you Escalate the Case after 4 days for EBay to Step in.