Paid fine because of booking two tickets together 🤡

I'm traveling with my friend for the Holi vacation. We booked two tickets through UTS. When the TTE came, we showed him the tickets, but he imposed a fine of 620 rupees on us for not booking the tickets from different IDs..

I mean, what does this even mean? It's an unreserved ticket, not a reservation where we have to provide names or other details. How can I sue him or report this incident? In no way is this fair. A ticket is a ticket...