Fortnite V-Bucks are nonrefundable (at least they're still marked that way on their site). Their Epic Games Store policy says: "Also, most in-app purchases are non-refundable", so that seems to extend to other games in their store. Epic used to ban Epic accounts after parents used chargebacks (so you lose all your other games, even ones you paid for); it became a big enough controversy (since chargebacks are the only option) that they softened it and now they just ban the credit card. In comparison, every Apple IAP is eligible for refunds and Apple is pretty liberal about granting them.

I assume that one of the reasons Epic isn't as hated as EA is that "the TotalBiscuit audience" is too old to be in the target market for Fortnite.