Can I show someone who sold me their fortnite account and doesn't give it to me?
Theoretically yes, but since you have the burden of proof, it's difficult. You should check in advance whether this does not violate the terms and conditions of the game.
You are welcome to try. But since account trading is already prohibited, you don't really have good cards.
Why do you do that at all?
Regardless of whether this violates any terms and conditions or anything else, the person who wanted to sell you the account has made himself punishable. The latter apparently acted with the intention of illegally creating an asset advantage. This is called fraud and is punishable under § 263 StGB.
See also:
https://dejure.org/gesetze/StGB/263.html
You can only sue legal matters. Account trading is definitely excluded from Fortnite's terms of use! (You must have read them ^^)
Try to claim your money back or book it back! A withdrawal from the "contract" is definitely (legally) possible!
Then that's bad luck. There are corresponding exchanges on which you can trade with accounts of all kinds (including Fortnite). There you can optionally carry out a transfer via a middleman from the respective portal. In my opinion, this is the only method that is safe for both. Otherwise, in the case of virtual goods, there's actually always no buyer or seller protection.
That works on portals like "PlayerUp" or "epicNPC".
