<human>: Can you summarize the given text in a few sentences?

**Backstory**: So this morning my sister needed to catch the train into the city, and she normally asks to use my Myki, which in Melbourne is what we use as a ticket which we load money onto, an touch our card on a sensor which deducts money based on the trip. Anyway she normally asks me if she can borrow it and ahs me back the money afterwards, but recently she had been using it without my permission, and hadn't been paying me back. 

**The Revenge**: I knew she had to be in the city this morning so I went online and cancelled the remaining $3.46 from the card, meaning there wouldn't be enough for the trip into the city. She called me after the train left saying she missed the train "because she couldn't touch-on". Touch on being the stupid thing they call scanning your card at the start of a trip. And I spent the rest of the day imagining her frantically and continually trying to activate her card, as the train shows up and then leaves without her.
<bot>: Sister steals train card and doesn't pay me back, I make her miss her train and I enjoy envisioning her missing that train over and over again.