Can I as an Apprentice removed before my contract with my company?

I was employed as an Apprentice on 3rd July, 2017 with Lionbridge technologies pvt. ltd in Airoli. According to my contract as an Apprentice I cannot leave the organization before the contract i.e., 1 year. Now, only after 5 months they have asked me to leave by December end. I want to know if this is legal. (I read Apprentice Act) the reason being company policy and they cannot keep me. in Appointment letter they have mentioned that they can terminate giving any or no reason, but this is not proper reason and I have come to know that I was just a replacement for her as she was on maternity leave and now coming back so I am being removed. according to contract if I leave before 1 year I will have to pay 15K. Now they want me to give 15 days notice and leave. This was my first job in IT field and they have spoiled my career as where would I go with any experience. Please advice and let me know I want to fight for it if this is not legal as I feel it is not. My career is at stake. loss of wages, loss of opportunity. Please!!