Company not Giving Relieving Letter after Termination.after 85 days they are asking salary back

I have 11 Years experience in IT.(here worke as senior devolper for past 1 year ).Company not Giving Relieving Letter after Termination.after 85 days they are asking salary back now. They told/sent LWD(2nd Aug) on mail and committed to give within 45 days we are giving releiving documents.But they are not responded upto 45 days.on 45th day i called asked we framed new rules,please provide form-16 of previous organisation.I told idon't have form-16 i will provide Bank statement.(After Reliving no right to ask any docs for the company).but i provided and i sent my ITR also.online also they checked both.i filed ITR as a consultancy income(half of the salary.because no form-16 for previous all organisations).after several days they asked again remaining companies bank statements and i provided and told 2 companies are in strike off as per mca.gov.in. On 85th day they are telling we not considering your previous exp and pay back salary.what can i do? in this situation.today 89th day from my LWD.(last working day).How can i get my Relieving documents?