Today, I unknowingly used a MYKI concession card which covers up to an age of 16 when I recently turned 17 last month. I either had forgot or never knew that after 17, I will not be eligible for a concession. I was stopped at the station by authorised officers who had said I might be issued an infringement notice for making an offence and said that I can appeal since it was my first warning. They asked if I can get anything to prove I am eligible and I didn't at that time, so they requested for my address, name and all personal details. Now I am stressed because this was the first ever time I have encountered anything to do with fines, and I was pretty shocked (I still can't believe) this has happened. I basically had forgot I'm not allowed to use my MYKI anymore since I am not 16 anymore and never thought I would have to encounter an experience where I have to pay a fine as I always make sure to touch on and touch off and have a valid MYKI. I have not told my parents as they would be really angry. I don't know what to do, let alone appealing towards the fine. I am just really hoping that I don't get issued an infringement since it's the first time but it doesn't seem like they are lenient. Please help.