Generally it is not necessary to talk to anyone to return an item that is not as described.
Start here:
https://www.ebay.com/help/buying/returns-items-not-received-refunds-buyers/return-item-refund?id=404...
Choose "does not match description" as the reason for the return if the seller sent the wrong item. The seller will be required to refund you directly or provide a prepaid shipping label or pay for shipping if overseas. If the seller provides a label, send the item back, and the seller should refund you once tracking shows delivery back to the seller. If the seller does not cooperate, after three business days you should be able to ask eBay to step in.
If you have questions or get stuck, post a follow-up here.
