Item advertised as new but the box is for a different model and has been opened

[rjgl4ever]

What should I do?

[countessalmirena]

It qualifies as SNAD/INAD (Significantly Not As Described/Item Not as Described). You can open a return request under eBay’s MBG. The seller must accept the return and provide the return postage label which you can print out to return the item as seller’s cost, and you’ll be fully refunded when the tracking shows the item’s been delivered back to the seller,

Read eBay’s MBG page for all of the details, including timeframes (which have no wriggle room). https://www.ebay.com.au/help/policies/ebay-money-back-guarantee-policy/ebay-money-back-guarantee-pol...

If seller doesn’t respond satisfactorily within 3 business days of your opening the case, an option to ask eBay to step in should appear.

Don't close the dispute until you have been refunded. Don’t let the dispute time out; it will close automatically (with no refund) after 21 days. If you need to escalate, do so within that time.

However, if you’re still happy enough with the item, you may want to keep it and perhaps inform the seller of the issue; give the seller the opportunity to explain or apologize and possibly offer a discount if the model you got is worth less than the model stated in the listing.

Up to you.