Disputes are filed by auctioneers when you fail to pay your invoice within the allowed time frame.
Please always check the auction house's payment terms to make sure that you will be able to pay within their time frame. Disputes may affect your ability to bid in future auctions--please try to resolve disputes quickly with the auction house. You can contact them through the contact information on the invoice that was sent to you or by clicking on the "Ask a question" link on any of their listings.
To view your open disputes and easily contact the auction house, visit your Won Items page.