Let me share my experience:
i have the same trouble as you(World Gate), my immediate reaction is to call my visa, however, the lady said that :" Credit card is not like cheque which you can cancel anytime you want, youhave to contact priceline, not the visa to have refund"
therefore, i emailed a lot a lot back to priceline, their responce were always always: priceline is nonrefundable!!!
i was so upset, since i was expecting somthing closer than world gate. that i again send TONS of email to them(i tried to call them, it is always answering machine, I NEED TO TALK TO SOMEONE!!!)
FINALLY, a manager replied to me that she will call me back the next morning.
The next morning, she called me, very nice though. She offered me last chance to rebid, if success, she will refund the previous bid minus the process fee(5$), which i am glad
i'm sorry for the grammar, since, till now, i am still not 100% satisfied with priceline, because their customer service is so difficult to reach!
hope this can help

good luck