You can check this thread.
In short, JC Sports was unable to fulfill a turbocharger kit group buy after 4 months beyond their forecasted delivery date. Their repeated poor customer service and misinformation caused me to take them up on their offer to cancel my order. The requested refund is for the $1000 deposit I placed for this kit in October. Quite a few people in that buy decided to cancel.
I recommend you do a search on the board for JC Sports before you decide to deal with them.