Buyer sold the item they bought from me after receiving a refund

[mloda6000]

I have listed by mistake a wrong  size of coat in the description. Someone has bought it and let me know that the size is wrong.I have apologised. Then issued a full refund and said I will send them a free return label. After they received a refund they told me they've sold the item.And left me with negative feedback! How do I get my money back? Can't find a help on the app?

[tobiasd4]

You should have sent returns label and only refunded on return. 

As you refunded 1st, ebay close case and label not available. 

This is now between you and buyer.