HR not providing experience letter

Hi, I worked for a company in mumbai for 1.9 years. I sent a resgnation letter to HR and my immediate manager and the same was accepted by them and they gave me a last working day at office( 45 days of notice period). I was serving my notice period. Meanwhile, after 30 days i did not get my salary. When contacted HR, they said they have blocked it and will not provide salary in notice period. They informed me that i will get all my money only after completing my notice period. As i live on monthly salary i i wont be able to manage without salary.i explained it to HR and HR started speaking rude saying it is not his problem and he dont care about my finiancial problem( offer letter does not have any clause regarding holding of salary during notice period). I tried explaning my situation but HR was so adamant and spoke stuffs like i can throw money on your face. It is not a big deal for not here to listen to your stupid problem etc. I sent a mail to HR after so much insults i wont be able to work there and said i will pay my compensation for the last 15 days that im not going serve in the company. Immediately they credited my salary. But i told i will leave and they can calculate my dues and i will pay it. After few days i contacted HR documents( exp letter etc) hr asked me to come to office. I had an interview on that particular date so asked hr to give me another date but hr said accountant is busy and wont be available on other days. Since i had interview i didnt go and i got a new job so i didnt bother to get the docs.. Now im in need of exp letter from that company. I mailed them but hr didnt reply. Im ready to pay them. Kindly advice