Oh dear, you should have accepted the parcel and then opened an "item not as described" (i.e. the box was empty) case under eBay's money back guarantee.
Have you checked what the Evri tracking record states? The bad news is that if it is recorded as "delivery refused" you will have rendered it ineligible for eBay buyer protection.
If all else fails you may need to try PayPal or your credit or debit card issuer, to see whether they can help. However, you may encounter the same problem - that delivery was attempted, but you refused it. It may help if you can get Evri to try to get written confirmation that it was clearly an empty box. Start by checking what the tracking record states.
Sadly buyers often throw away the protection that eBay provides by failing to read and follow their rules correctly. The T&C state that damaged packing or empty boxes should be treated as not as described, which will require the buyer to be able to return whatever was received. It's possible that your empty box just contained a paper clip or elastic band, a common trick to get proof of delivery. The best possible outcome for a dishonest seller is if the buyer refuses to accept it. Good luck anyway!
