Paid by bank transfer but received an empty box?

I bought a laptop on eBay Classifieds by wire transfer. Then I got a package sent with tracking. When the package arrived I signed the postman and looked inside. There was only sand in the package, which was about as heavy as the laptop. When asked to the seller, he said that he had put a laptop in there and either I or the postman took it out. What should I do now? I didn't receive a laptop, but also no evidence that I didn't take it out? Can't I do anything about that now?

No, only works when opening with a postman. EBay has been warned against buying for tricillion years.

The package was intact, which clearly shows the fraudulent intent.

It is not for nothing that warnings are given when it comes to classified ads

https://themen.ebay-kleinanzeigen.de/sicherheitshinweise/

Unfortunately, you can't do anything about that. There's no evidence of who poured in the sand.

The answer from the seller is so stupid, even if the postman had stolen the contents, where would the sand come from? : 'D

You can only file one complaint and hire a lawyer.

Does the seller's address appear on the package? Sometimes it is enough to pay a "nice" visit and say the facts out loud (!) So that the neighborhood is entertained.

In principle you can only report it in the hope that the seller has been on the tour several times and that this can be proven to him. Leave the package with the sand as it was! Otherwise it looks bad!

Thanks for the answer, I'll have to do it. The seller gave me his number and I called him and he said that I put the sand in to get the laptop for free. Who is more right in such a case, the seller or the buyer?

The problem is that statement stands against statement.