No one is able to simply take your money out of your balance, so no one stole it from you. The only way this can happen is if you have a shop sign (or chest shop) where you are buying from players. These are the kind of signs that say "S" in front of the price, on the third line. Check your plot (I assume this is on prison) for any chest shops. Probably what happened is someone sold you a bunch of whatever the chestshop was buying, such as tokens, for example, which automatically takes from your balance.
In addition to his response, the only way the Admin Team could do something would be if you had a recording that shows that you're losing money and it's on the server end, otherwise nothing can be done.
