THE most important thing to have to send to your credit card company, is a copy of an email or some other statement by the seller where he indicates he will send the item in return for the amount agreed. I assume because this is evidence of fraud - if there's no promise by the seller to give you anything, then he cannot be found to have defrauded you.
I had to do something similar last year, I sent my CC company ALL correspondence I had with the person who defrauded me, which I had kept. They recovered everything in the end, and even refunded the interest accrued on my CC as a result.
Incidentally, this was a result of an eBay transaction. Despite frequent contact with both eBay and PayPal, eBay did nothing (inasmuch as the user's account remained active and eBay didn't compensate me) and PayPal refunded me something like 10% which equated to ~ 30GBP....
Good luck guys