High school credits.........?

I went to an alternative high school junior to the beginning of my senior year. I then moved to a new town which put me in regular high school. Well my. Old high school needed 21 credits to graduate and my new school needed 28. So they put me in as a junior. Keep in mind i was in alternative high school which is meant to keep kids who want to drop out from dropping out. So i wasn't happy. Now the end of my senior year they decided to inform me i dnt have a computer class required credit. So i am meeting with a computer teacher in my spare time to get one. I live in Connecticut. My question is is it illegal to kick a student back a grade an not accommodate their previous schools credits? The funny part is a girl went to my new school for 3 years an switched her junior year to my old school. She went back her senior year and they accommodated her with 21 credits even though she. Was only in a my school for one year. Is this illegal? I've tried finding out but i can't get an answer anywhere. I may be doing another year if i can't find out. And i was already pushed back a grade because the credit difference. I want to go join the national guard but i don't want to until i graduate. And a sixth year in high school is not what i want. Someone please help lol