Experience and Releving letter

Hi sir, Hope you are doing well. I’m here to explain my situation regarding my employment. I resigned to my old company on 17/07/2020 without any pending tasks and works but I haven’t served notice period of 90 days due to medical emergencies. I was asked to pay some amount of 28700 for F and F settlement as I haven’t served notice period. As I was in medical and financial emergencies I haven’t looked over the issue. Currently after 1.2years I’m willing to restart my career to follow my future. In the process I got selected in a new company and they requested my releiving and experience letter within 18/10/2021. So I cleared the F and F settlement amount of Rs.28700 on 06/10/2021 to the old company and when I asked them for my experience documents they are saying they need a time of 5 weeks. However I explained my situation they are not able to provide me with my documents. The certificates after 18/10/2021 are no use to me as I already lost a very big offer by then. Can you please help me what legal action can I take to get my releiving and experience letter within 18/10/2021? Hope you will help me in solving this problem. Hope to hear from you soon. Thanks and Regards, Rachana G