Regination with short notice period

I have resigned from my post after working for 1year 4months for this organization. I have given very short notice of 7days (resign on 26.07.16 and last working day was 31.07.16) for the reliving against my notice period of 2months. I ask them to tell me the full and final status and amount because I am ready to pay the money for notice period. But still they said that they is nothing left to deduct as I have resigned after salary date and took all the money and threaten me to put my case in absconding and will take legal action on me. Where as I have more than 30days of leave and my LTA money is also with them. They told me take some more time from my future company and give the 15days notice period. I took 10days extension time from my future company and working here. Still they want me to work more and not ready to give me reliving and experience letter. My question is how will I manage this situation. Can company take any legal action on me? Can I Leave this organization on 10th of August after completing 15days of notice period? how will I get my reliving letter and experience letter along with Full and Final?