This is serious. The size of the problem depends on the purpose of the school. Usually, the counselor in charge of household registration applies for many cards, and the bank card issuer gives a kickback. If you don't get the card after applying for it, the other party can swipe it. But you have to pay back the money. Overall, at the very least, you should call the bank now and ask to see if there are any outstanding balances on your current credit card. If you don't cancel it immediately or report the loss and get a replacement card, the original one will be useless. If you are already in arrears, of course you should sue the school. This is illegal and even criminal.