@OP (because that name is not one that trips off the tongue or is readily typed),

If you have the receipt from an authorised reseller of Nike shoes, it could be worth your contacting eBay CS via chat, and stating that you have the actual receipt from an authorised reseller. Explain that on that basis, it would not be correct for eBay to force you to accept a return, particularly as you are worried that the buyer may do a switcheroo.

Ask if you can email a scanned copy of the receipt to the rep. Ask also if, having received it, the rep would be prepared to close the return request on the basis of this being a fraudulent claim.

eBay's Report an issue with a buyer help page states:

❝When to report a buyer

You should only report a buyer if you think they're violating our policies. Here are a few examples of when to report a buyer:

• [...]
• You believe the buyer is making a false claim
• You believe the buyer is misusing eBay Money Back Guarantee or the returns system
• [...]❞

Reporting the buyer is as simple as clicking a button, choosing the relevant item number, and outlining clearly what the behaviour is, and which policy or policies you believe it breaches. (I suggest in point form to avoid getting carried away with writing a three-act tragedy - oh, how well I know the three-act tragedy temptation!)

This is the Abusive buyer policy . Buyers whose behaviour demonstrates breaches as covered in this policy can be reported and it should have an impact on any decision made with a particular returns/refund case.

Specifically, this is the sort of breach that you allege is occurring:

❝Behaviours we don't allow

[...]

 

   Not allowed

• Claiming an item was not received when it was delivered
• Claiming an item was not as described in order to return the item when the seller did not offer free returns❞

(Rubrication mine.)

               Report a buyer

However, do not allow the eBay CS rep to escalate the claim/dispute unless you have in writing that they will find in your favour, automatically closing the dispute or words to that effect.

The retail shop from which you seem to have purchased these is certainly an authorised seller. F**tl*cker do, however, have these listed on their online shop for less than half of the price for which you listed them. It is entirely possible that the buyer kicked him/herself after seeing that; the number of people who compare prices AFTER buying something is surprisingly large.

You can put it to the CS rep that this gives the buyer motive for wanting to return the items for a full refund by misusing the eBay Money Back Guarantee with a fraudulent claim of "not authenitc". Wanting to return an item because the buyer found it cheaper elsewhere is not a reason for initiating a SNAD return. It's classed as a change of mind return, and you have stipulated "no returns" (which means no change of mind returns) in your listing, so the buyer's options are to

                    a) suck it up, or

                    b) make a false claim.

Bear in mind that when communicating with eBay CS staff, you must be polite, persistent, and patient.

Best of luck.