Most of railways in Czechia are operated by Czech Railways. However there are few places where private companies exists such as Railways Desná. When you need to use only one of them, everything works fine, but travelling with both looks sometimes like a big trouble.
You have no problems when starting on private one, they sell you ticket for whatever you need. But Czech Railways only tell you, that there is private railway and you need another ticket. They don't bother to tell that you can buy the ticket by them. So you travel with Czech Railways, switch to private with no time for buying another ticket because Czech Railways are allways delayed and now you have to pay penalty because you don't have your ticket. Funny, isn't it?