Was this fair, considaring I'd done nothing wrong?

I was going to meet my friends at the train station, I put my ticket through the barrier when a man stopped me, he pulled me aside and said..."That's a child's ticket, your not a child". (In the UK a child travel ticket is for anyone under 16). I'm 15. Then he called another male member of staff over. They were both huge, tall and simply intimidating. I pulled my oyster card from my purse, which proved my age. He snatched it out of my hands and asked me my birthday, so I told him. He later asked twice again, and I told him. Another man asked my name, and I told him without hesitation. He then pointed at cards in my purse and made me show him what they were. So I pulled a library card out, with my name on the back... They just kept saying, "I don't believe you, you don't look fifteen", so I told him call my mum, but he wouldn't, in fact he replied with "Call your mum? Your lucky I'm not calling me police". He had no way to prove I was over fifteen, so he told me he was keeping my oyster card because it was slightly scratched. I told him I couldn't get home without it, this point I was practically in tears but he refused to give it back saying "I should be calling the police, count yourself lucky". I can't help looking slightly older than I am, and he treated me like a criminal for it...