Training Agreement (3 Days Boot Camp)

Dear Sir, I haven't signed any agreement at the time of joining (employment agreement). But after two months my company had nominated me for 3-days boot camp and I was compelled to sign Training Agreement in Non-judicial stamp paper for attending the 3-days boot camp with estimated expenses of Rs. 15000 only once. The agreement states that, If the employee happens to resign within 2 years after the training (3 days boot camp), employee has to pay the training expenses amount. Later company had also sent me for various meetings/trainings, but I haven't signed training agreement in Non-judicial stamp papers for these meetings/trainings (except above mentioned 3 days boot camp). Now I want to resign from my job. But my employer said that, I can resign only if I pay the expenses of 3-days boot camp + all other meetings/trainings I had attended so far. I am confused. Please help me. I have worked for 15 months already. How should I resign ? How much I have to repay ? Please help me out. Thank you..........