Non payment of corporate credit card bill

Hi ,actually I have a corporate credit card which was issued by my employer. I was working there as a trainee that time with a stipend of Rs. 10000 and my credit card bill after 8 months was 70000 and I actually paid 52000 already but after 1 year of job , I left my company and my credit card got cancelled and there is still some amount pending but I'm not doing any job right now and I'm still paying 1000 per month but I'm getting calls daily from the collection agency for the payment and its damn scary. I dont answer the call because they speak so rudely and I'm only 22 years old and right now I'm unable to repay the loan. So kindly help me what to do in this case. I told them earlier also that I'm a holding a corporate card so if don't pay my company will pay but they are still threatening me and calling me daily.