Why are my goods and services payments being refunded?

[Aurrix]

I am a seller on a website, and every time the people send a payment to receive the item, their payment is automatically refunded without my having refunded it myself.

This is confusing me greatly, why are all the payments being sent to me being refunded? 

[Tirb]

My listing on Ebay said no refunds.  Ebay refunded the scam artist anyway and stole $145 from my PayPal account - how can PayPal let them do this????