You have returned the goods and have tracking proof that they have been received.
Invoice them for the goods.
They can claim that the goods were never ordered so you will probably have to pay to have them returned.
Forget all the history, you've been caught. If they had the money you would have been reimbursed by now.
A CCJ is the result of a successful small claims court action and a failure to pay.
Post the name on here, they may threaten court action, but if they haven't got the money to pay you, they can't afford to take you to court.