Fine for entering Dubrovnik

We visited Croatia last year in July 2025. I got an email from my rental car in April 2026 that I entered an unauthorized zone and they are charging the rental car company 1,580 EUR for each infraction of me entering the “unauthorized zone”

At this time I don’t remember what happened back in July 2025. Also I thought there was no parking so we always parked in a garage. Now I am finding about this ticket.

Does anyone know a good lawyer or have any experience with this? I have heard if I ask the authorities to charge me as a natural person then it’s lowered? Is that true?