Please help! freezing a debit card account?

long story..sorry about that. but my boyfriend isn't really a nice guy..yeah. i know i shouldn't be with him but whatever. ANYWAYS, he stole my debit card from me and he knows my pin and since he's in trouble with the law he's putting $2000 on my card. i'm 16 and he's 20. i just want my card back and he won't admit that he stole it, he's saying it 'fell' out of my wallet when his parole officer had to go through my bag. but anyways. how can i freeze it without my parents knowing? it's a student account too if that has anything to do with it. thanks for the help!