Company not paying salary after resignation

Hi, I worked for a company for about 9 months and had to quit due to health problems. I trained the person who were taking over my responsibilities, served double the time of agreed notice period and even provided help after that. 31st December was my last working day and Company promised me to pay my retention amount and salary on upcoming payday i.e. 7th January, the amount sums up to be 90,000 INR. After 45+ days of leaving the company, they are procrastinating my salary and accusing me of damaging the laptop I was using, which was working fine when I handed over to my successor. After several phone calls, and visits to the office, and warning them of legal action, company proposed to pay me 60,000 INR in two installments because they have liquidity issues, that is none of my concern. Company is also threatening me of blacklisting and giving bad references, even though I have been a good employee and brought frequent business to them. I want my salary paid in full, I will really appreciate if you could advise me how to take this case forward in legal direction, and how long does it take for such a case to be addressed in Ahmadabad. Kindly advise. Thanks