They did not believe me and took me to another person who forced me to pay 800 Kronas as a fine. They said if I refused to pay, I would be taken to the police station.
Ticket inspectors cannot make you pay anything. As outlined on the official Prague Public Transport website:
The authorized person is entitled to:
- impose a supplementary charge on a passenger who failed to show a valid ticket, or require the passenger to disclose the personal data referred to in paragraph 1), letter c).
Therefore you have the right to refuse payment on the spot and simply show them your passport. They are authorized to write down the details and issue you a fine, which you may pay (or contest) later on. They could only ask you to go to the police if you refuse to provide your passport/ID, at which point the police will find out your personal information. The ticket inspector is not authorized to use force, as he's merely an employee of the transport company rather than a police officer.
How can I prove my right in such cases?
Before giving your passport to the inspector, ask that he writes the reason for the fine on the penalty paper and puts his signature down, so that you can prove the origin of the dispute because otherwise you wouldn't be able to show the 1/7 confusion was the source of your problems. After you have the penalty statement, you may visit the Penalty Fare desk and contest the charge.
However I wouldn't set my hopes too high — the public transport authority would usually only accept disputes over personalized monthly tickets, rather than anonymous temporary ones, since it's hard to prove you didn't get someone else's ticket after you've received the fine.
Was I scammed?
We cannot know for certain, but future readers could be advised to avoid paying anything on the spot if they have doubts about the legitimacy of the ticket inspector. Instead, one can take the penalty paper and pay it in cash at the Penalty Fare desk or pay online using a bank transfer.
If the public transport agent insists on paying on the spot, I'd advise calling the police myself to sort it out, as it's likely that those people are scammers. Do not worry about issues with the police, they're much more pleasant than the ticket inspectors.