For buying on-line bike parts, I have always dealt with Dennis Kirk. They're not the cheapest, but their service is excellent. I actually just bought a front storage box for the King Quad from Rocky Mountain ATV, and their service was super, too, but the shipping took 7 days when I usually get it from DK in 5 days.
Either way, both seem better than your experience. I like DK's website because it will tell you if the part is in stock and how many are in stock. Plus, their phone operators are friendly and accept calls 24/7.
Sorry you're getting the shaft. If you paid with a credit card, try calling the credit card company and see if they can reverse the charges or put some pressure on them.
Jerry