It's an old scam - someone buys something from you on a selling platform like eBay or Mercari or many others now, they pay, you ship, it gets delivered and then the trouble starts. The reason might be the product was damaged, it was never delivered, it was not what they thought they were buying, or there was a difference in the description and what they got or something else. The buyer immediately wants a refund or else. Do you give it them?
Hell, no.
The refund/chargeback scam has been around for decades. I've been a seller on eBay dating back to 1998, and it comes up again and again. Interestingly, the platforms take forever to do something about it as well, usually taking the side of the buyer by default and then only protecting the seller when the abuse gets to the point of the police getting involved. By then, for most, it's too late.

The strategy is simple - the scammer's goal is to get both the product as well as the payment from the seller using the legit refund processes. And, the refund scam becomes even more blatant on platforms that make a big deal of protecting buyers at all costs carte blanc. For the sellers, it's a misery at multiple levels. First, there's the angst of dealing with an unhappy buyer thinking that some communication might fix things. It won't but it draws in the seller to be primed for the threat. "Refund me immediately or I'll blast your reputation online!" Some sellers are so worried about one bad review, even if false, they will bend over backwards to avoid it. Second, if the refund does get approved, usually now by an AI bot, the seller is out the money and the good product that was shipped out. Third, then there's the risk of the whole problem happening again. After all, if you pay a ransom once, you're likely to get targeted again.
The chargeback version uses a payment by credit card and then, when the seller gets the item, they complain to their credit card company it was fake, and the credit card company reverses the charge. This version is even more annoying because you literally have no control as a seller to prevent it; your credit card processor betrayed you. It was very common in the early days of reselling, but since then it's tapered down a bit with card investigations happening first.
There are some basic defenses a seller can use. The most obvious is to make it clear buyers are buying AS-IS with NO WARRANTY and NO RETURNS. Literally, put that statement in the description of what is being sold, and maybe the title too. Then, only describe what is photographed as basic as possible. In fact, I often use the platform's AI to do this now, because then I blame the platform for the description. So far, it seems to work with the bots.
Next, if you do get a demand for a return anyways, you have two choices: go nuclear and say "No," and you'll probably get a bad review. If your overall history is long and good, who cares. Move on. If you're a brand new account, however, then the second option comes into play: offer a refund ONLY if the buyer sends the product back completely shipped at their cost. Once you have it and confirm it's the same, then refund promptly. Call it a day, wash your hands and move on.
And block that buyer from ever dealing with your stuff again. Make this last step a critical rule in your business process. I don't care how much they promise to buy again; they are persona non grata as soon as this shit starts flying with a refund claim.
Finally, don't sell high-priced items of mass-selling online platforms. They are a big risk for refund/chargeback scams. Use escrow services or more legitimate platforms for things costing more than $250. They might have more in fees, but the peace of mind is worth the trouble. An escrow service provides an objective third party who confirms the goods sold and the money paid are complete and then sends the two to the buyer and seller after confirmation. This avoids helps avoid refund fraud, and the buyer loses any defense of saying they were duped.
You're going to get some lumps selling online. It happens to all of us, but with some good risk management you can keep the damage low and keep your business producing income.
