Data theft conspiracy

Hi , I was working with a firm from past 3 years but on 8 of June I planed to leave the organisation due to salary issues and then I cane to know I could can work with the competitors on my own so I gave my resignation on 10 and the I was serving my notice period and was working for the competitor while I was employed by my company and then on 15 of June my employer came to know that miss using his data for my benefit and then they forced me to work with them but I said no then after that other day I called my boss to ask what to do next do I have to serve any kind of notice or not he said that no need to serve notice period. After that they didn't gave me any letters regarding to my employment with them and they not even cleared my fnf and after 2 months they are now forcing me to sign some bond and affidavit stating that I don't have any data n all with some third party clause and all .but I am not signing it so they have now send me a legal notice.also when I left the organisation they took access of my email and took the payment from other competitor on some random guys name.n now they are saying that go and prove it that company had taken the payment.also they are not clearing my remaining due also they are not giving me any papers or documents regarding my employment with them and the important thing is company never took my initials on company's code of conduct or NDA nor they gave me any appointment letter.