Personal loan defaulter because of job loss

Hi, My sister took personal loan from hdfc bank. At that time she was working. We paid the emi for an year and after that she lost her job. And after that on this january we paid a sum of 50thousand to personal loan collecter who came at my place. Today i got a letter from postman, firat the postman was not handling me the letter as it was in my sisters name. Then i said she doesn't get time to collect the letter from post office as it is closed on sundays. Then he handed it to me. The letter was having 4-5 pages and that was reminding us about the case filed in court and about the 4 hearing that happened in court. The same post office scene happened 2 times ago, my sister was at her job and she only gets one leave and that too on sunday. So the postman didn't gave me the letter before and my sister employer did not allow her to take holiday. So we didn't collected that letter and i think it was the hearinging notice as mentioned on the latest letter. According to letter they wrote us 4 notices. And i am not aware of 2. The letter which i got today stated that my sister has not appeared for the hearing 4 times and there is details of each and every hearing. We are willing to pay but needs some time to pay. But whenever we try to talk to the bank they send recovery agents and they repeat the words like you have to pay it now we can't offer you time. No one is ready to help. When we made the payment of 50 thousand se asked the man who collected to grant us more time. And he said u have to pay again next month. He was not helping. Please tell me what can we do so that she doesn't fall into this court cases and which can lend us some time to pay. We never denied for the payment of loan but ae need time. My mom is indian navy pensioner my dad is no more and i am also looking for a job. So our finiciaal situation is not that strong now. But willing to pay the loan after 2 months. Please help