Drop shipping from Ebay scam

Wondering if anyone else has experienced this. We have a high volume ASIN, which we only sell D2C through our own website and Amazon. In recent months we've had a massive increase in returns on this item, but the products are never returned, just refunded.

We've also had a lot of Ebay drop shippers pop up. They are purchasing from Amazon and then seemingly claiming refunds. Each of these refunds I can see, as the names on the refunds are odd, maybe letters in the names mixed up such as Jhon instead of John etc. Sometimes the same individual will be refunded more than once on a day for orders shipped to different people. When I click into the order, the shipping names don't match the refunds - by a long way.

I have tried to raise a case with Amazon over this and they don't seem to want to know. Ebay are super slow in doing anything and if they do remove the listings, these sellers just pop straight back up a week or two later.

In an attempt to stymie this I set up our own listing on Ebay, at our correct RRP so that I would be undercutting the drop shippers. However one has undercut our RRP by £1. This to me proves that they're selling then claiming a refund, as otherwise as a normal drop shipper they'd actually be losing money!

Has anyone experienced similar, or have a way to deal with these crooks?

Thanks