Absconding with intimation to company

I have resigned from my position officially. the official notice period is 3 months. after 1st month of notice period company paid my salary, after 2nd month company said we will pay you your salary, but after the last day of 2nd month (when salary used to get credited) company said you need to do KT and do additional work, after completing that we will release your 2nd month salary. after waiting for 15 days more in company (without having salary), I wrote to management that, i cannot work from office, as i don't have money to survive in city. I will move to my native and complete rest of the 15 days working from home. over this email, company wrote we cannot accept work from home, you have to complete remaining 12 days from office and hand over work and KT, else we will take a legal action against you and charge 1.8L for loss of business. I have provided work to company what i when i was working from home. Still they are trying to threaten me by legal action and penalty of 1.8L. Please suggest what action i should take.