There are both genuinely sincere people and vicious low lives where ever your travels may bring you. In other words, transferring schools will feasibly bring you similar experiences and results if you don't learn how to handle the situation properly in the first place. With any negative experience, the best we can do is try to grow as a person because of them, not degenerate from them, otherwise we are also a bully to ourselves.
A positive mindset goes a long way... I remember in my elementary and middle school years, I always felt sorry for myself and thought my life was the most melancholy. I had the most negative outlook on everything, but then one day, I started working towards gaining a positive attitude. It was hard, but I was truthful with myself, and started making my own happiness through my attitude, my outlook, and how I would let future events impact my life. It may seem impossible to work towards if you are in a depression state, but sulking excessively makes everything seem 100 times worse than it actually is. One day in middle school that phrase hit me like a bullet. I was depressed back then, but all it took was the motivation to gain a positive attitude on life to make my own happiness. Now, I'm a completely different person. Maybe one of the happiest you'll ever meet. Even during bad times, somewhere deep inside I'm still happy. I'm so happy that sometimes it really annoys me. It's pretty great
Now I understand you dislike these people who have hurt you and betrayed your trust, but you are subconsciously allowing them to manipulate you, even when you try to physically escape through avoidance. You see, that's only one piece to the puzzle...but you need every aspect to form the entire picture, otherwise it will only be a temporary shield that already has many holes.
But you know how I see this? I see it as a blessing you saw the TRUE colors of your so called "friends." If Person 3 has the lack of propriety and decency to refuse to return a possession of yours and attempt to deceive you about it, then it's good you rid yourself of someone that doesn't deserve your companionship. If a person cannot appreciate the trust, faith, loyalty, and admiration you instill in them enough to honor it, then that shows that they are not worth your time.
It's how we choose experiences to impact us, and recognizing the different forms we can take to achieve the best strategy to handle them. We all have a choice in any matter, we just have to broaden our state of minds and perspectives to acknowledge what those choices are. Look to yourself and remember that you can allow a negative experience manipulate you, or you choose to manipulate the experience to your highest advantage.
At the end of the day, it was never the experience that tore your defenses and made you drown in self-pity, or thrive in your pursuits; it was how you permitted yourself to deem what kind of control the situation had over you. YOU alone are in control of your own life, so prove the strength you hold for yourself by allowing yourself to take control. Easily submitting to your defeat and encouraging misery inevitably leaves unfulfilled voids; but taking action to get past that point will leave a life well lived with any given circumstances.
Admire what you once envied, find a way to thrive upon of what once degenerated you, and smile at what once made you frown by boasting your true colors. Those options are present, whether you see them or not. Disciplining yourself to this point of consciousness benefits you for the rest of your life...it takes some time, and it's quite a challenge, but it will improve your happiness overall.
By the way, you can get your parents to call the school and report that these girls stole your jeans and refuse to return them.