[Lemoy]

Why don‘t these people refund and sell the refunded items to get a lot more money than the small percentage they‘re getting by the customer?

They don't have just the one customer - they SE In bulk.

There's minimal to no risk for refunders who use their customer's credentials.

Well I remember that you told me 3k € would be the limit you wouldn‘t go further on my 9 y.o amazon account.
How do they succeed with fresh accounts up to 15k $ orders claiming they have a high success method?

How would you do it if you‘d go for a personal refund which is at that high value?