Ignore the 'seller doesn't accept returns' bit. eBay views that as referring to returns because a buyer has simply changed their mind. The seller has to accept returns when the item arrives not as described.
Send a message to the seller, through eBay, stating that you wish return the item and receive a full refund. If you do not get a satisfactory response, open a SNAD (Significantly Not As Described) dispute in the eBay Resolution Centre. One advantage of an eBay SNAD dispute is that eBay's resolution team have access to any messages sent between you and the seller.
The seller has 8-days to respond to the dispute. Should they fail to resolve the problem, escalate the dispute and let eBay decide. If eBay instruct you to return the item to the seller, send it tracked and insured for the amount that you paid the seller (in case it is lost in the post).
Your refund will include the purchase price and the original postage and packing charge, but not the cost of returning the item. Though, a good seller would also refund the return costs, where they are at fault (inadequate packaging, in this case).
NB The time limit for opening a dispute is 45-days from the payment date. Do not close the dispute until you have received your refund (no matter what the seller may say or promise). Once closed, a dispute cannot be re-opened.
