Jessie come on, I know you've been on the BOI a bit. Since when does it work for someone to tell everyone "case closed, everyone mind your own business!" XD
You've fessed up to deliberately trying to short someone $$ at the expense of the snake. Yes you've refunded it now, that's a start, but it's hard to say why from here. So take your BOI licks.
Personally I'm on the fence: even in someone fairly young I don't believe morals sprout in just a year. At a guess you've just realized the negative impact bad deals can cause, and are now seeking to keep your rep good. Which is better than the alternative, but it raises the question of what you would do if you thought you could get away with it. On the other hand, I do believe people still in their teens can change a lot more, a lot faster, than older folks. So maybe you are a good guy through and through, or will be. The only thing that will prove that you are now a good guy is time and good transactions.
So, take your lumps, be patient, and work on showing you've changed if you really have. Building a good rep takes time. Building a good rep after you've done shady things in the past takes even longer.
I would strongly advise you to be honest even in little things, like the fauna age setting. If you "don't know how the fauna feels about younger members", why not ask rather than fib right off the bat? No it's not a huge deal to list online ages accurately, if you're not selling online anyway, but it's a good habit.