Cancel item wrong size

[nigr-5533]

I am new to eBay and the auctions. I won a auction and I didn't realize item is wrong size and wrong gender. I haven't paid for item. Won't let me cancel start a return and the seller is not replying. I have tried the chat with eBay customer service 4x disconnected. I'm extremely disappointed and 

[disneyshopper]

You can only REQUEST a cancellation.  The seller is the only one that can actually file a cancellation, and sellers are not obligated to do so, although most will if you ask nicely.  If you do not pay within 4 days, the seller can file a cancellation on day 5 for Buyer did not pay.  That will record an unpaid transaction on your account.  Two of those, and most sellers block buyers with 2 or more unpaid transactions from bidding/buying on their listings.  That block will last for 12 months.