Dealing with dishonest buyer

[habei65]

I sent an item to a buyer. 

Now, he claims that the item is wrong.

I am pretty sure he is not honest.

How can I proof that he has replaced my product with a cheap children cloth.

[pburn]

There are no sold listings showing up on your account. Did you use a different account for the sale you're asking about?

[mam98031]

You can't.  You are only guessing that is what the buyer did, you don't know for sure.  

Politely ask the buyer to expand on "the item is wrong".  How is it wrong?  Send pics.

If your buyer opens a request for return, you need to honor that and either accept the return, pay the return shipping and refund them once you have the item back.  Or you can allow them to keep the item if that is more cost effective for you and just fully refund them.

If they are only emailing you at this point.  Just stay nice, until they open a claim, you really don't have an issue.