Is flyhi.se Safe?

I booked a ticket from Prague to Heraklion. Booking and payment was easy enough. The problem is that the price I was charged was not the one listed! And that price was the only one shown when I paid. Unfortunately I found this not to be a mistake. This company clearly purposefully tricks customers. When I contacted customer service, I was told that while the price they advertise (and is the only one mentioned when paying) is in CZK, they actually charge in EUR. So the amount I am ultimately charged depends more on my bank than on them. They do protect themselves since they put this information is in the "Conditions of ticket purchase", which you have to accept to purchase the ticket. In summary, they put the important information in the fine print... They also send the invoice with the amount in CZK, which is nothing more than an estimate! I'm currently trying to get at least a proper receipt, in euros, since I do not have time to fight them to buy the ticket elsewhere.