It is impossible to state what you can do. We don't have enough facts. It sounds like there was an agreement -- an offer, acceptance, and consideration "paid." The offer to return you to the school if you leave for a year, your acceptance and performance, and the consideration being your willingness to leave voluntarily (if that were the case) and go to this other school. It's difficult to know what was said and also to "prove." The best way to handle this might be with written letters requesting and/or demanding that you be re-entered as a result of your performance of the terms of the agreement you made. Otherwise, you may need to hire an attorney to obtain an "injuction," and order from the court compelling your acceptance to the school, if possible.
It's difficult to answer. There are so many facts we don't have so the above is just a legal exercise supposing generic facts.
