If a buyer opens a return and you don’t respond to it in 3 days a buyer can request eBay to step in and refund the buyer allowing them to keep the item. Sorry, but eBay was doing exactly what the MBG says they will do when asked to step in.
Below is an excerpt of how to handle a return request as a seller:
When the buyer opens a return request we'll notify you by email (to your registered email address) and through eBay Messages. You have 3 business days to respond to the request and resolve the buyer's issue. We've outlined your response options below. In some cases, we may automatically accept a return request on your behalf.
If you're unable to resolve the issue within this time, the buyer may ask us to step in and help. In some cases, if you haven't responded to the return request, we may issue a refund to the buyer and seek reimbursement from you without requiring the buyer to return the item.
How to handle a return request as a seller.
