I know, you don't want to open up something that is under warranty, but you never, ever want to ship a CD changer with CDs in it. They will bounce around in shipping, likely getting scratched up, and possibly doing physical damage to the player.
Next time, carefully open the case, and you will have easy access to at least 4 of the discs in a carousel type changer, and likely will be able to get them all out. In most cases, it is just removing a few screws for the top of the case and then you will see that the discs that are waiting to play have nothing holding them down. (Other than gravity, of course.)
This also means that you want to move a CD player as little as possible when it is full of discs, and always keep it upright if you have to move it to remove the top to get the CDs out.