Bonded labour legal or illegal ?

Hi , 

I recently joined a bpo company in chandigarh and upon my joining i'as made to sign a bond for 1 year .It'as a non judicial electronic stamp paper of value rs 10 along with  attached aggrement .  i'm bit confused as far as i know there is no bonded labour in india ( not sure though ) so is it  just a scare tatctics followed by companies  or can they actually take certain legal action based on that bond ? .  they even denied  acopy of that bond .         

Regards

vikram