The star and her sisters, Khloe and Kourtney, were paid $25,000 to make a three-hour personal appearance at Manhattan nightspot Pacha on Tuesday (09Nov10) to launch the card - but club chiefs were stunned when the siblings left after just 45 minutes.
They subsequently returned to the bash but exited again shortly afterwards - and Pacha bosses are demanding the Kardashians return their appearance fee.
A spokesperson for the club tells New York Post gossip colum Page Six, "We are extremely disappointed. They did not fill out their contractual obligations to be there for three hours. We also paid Khloe's travel fees. We would like a refund."
But a representative for the sisters has blamed the incident on a misunderstanding, adding, "The girls did all the press and meet-and-greets they were obligated to do. There was a miscommunication between the club and MasterCard that was not relayed to us, and so we went back."