EBAY COMMERCE UK LTD is the company set up be eBay.co.uk to handle buyers' payments. When you pay eBay, whether by PayPal or credit card etc., your payment does not go direct to the seller, it is paid through EBAY COMMERCE UK.
The most likely way in which a buyer might be indebted to EBAY COMMERCE UK is if their payment was somehow reversed (e.g. for having paid using fraudulent funds) after eBay had already passed payment to the seller.
If you have checked your transaction record carefully and are certain that no transaction on your account could give rise to this my guess would be that eBay has mixed you up with an account having a similar name, and given their debt collectors your particulars in error. This has happened before.
My advice would be to write to Moorcroft Debt Recovery, by recorded delivery, and reiterate that you have no knowledge of the alleged debt and have never had any transaction on eBay that might account for it. Point out that you have acted on their advice to contact eBay, but that eBay has so far failed to reply.
Suggest to them that it is their interests to contact eBay themselves to establish why they allege that you have any debt to them. It will prove costly to both eBay and Moorcroft if they attempt any action to recover this alleged but non-existent debt. You could even point out that this would not be the first time that eBay had given debt collectors the wrong member's details.
You have nothing to worry about as neither eBay nor Moorcroft can demand payment of a non-existent debt. It may be you who ends up claiming your costs from them if they try.
