Why can't I log into Fortnite?

I changed my Fortnite name two weeks ago and wanted to change it back to unreal engine, but since that was my credentials are invalid. Then I tried it on the homepage of Epicgames and it said that it is still invalid. I've already tried to change my password, but I could not do that. Does anyone know how to log in again?

My insider tip would be to contact the support. Betrayal but no further, that's what everyone does in the end.

I already did that, but when do they contact you? And how do I confirm my mail?

It works now!