Fraud EBay Classifieds Coupon Code?

So I exchanged a Netflix Code for a Spotify Code on eBay Classifieds.
However, the code I got is not valid and the other one does not answer anymore.

Can I do something about it?
As a student 15 euro are already a lot of money.

You can learn from it.

15 euro lesson.

You can't do anything there

Well you can report that to the police, but because of 15Euro, unfortunately, will not do much, unless you know where he lives etz. Then the vlt. To do something.

In the classifieds you can sign up as Hans Wurst, Schnitzelstraße 11 in 11111 Frittenhausen. It would be a miracle if cheaters would contact their correct address