Medmonx Enterprises Pvt Ltd - Salary not received

I have been working with a company for almost * years as of now and they have not provided me with an on boarding letter and a contract which specifies notice period and other related stuffs. Upon demanding and asking for a payslip or any other legal details they would make excuses and not provide them to me so I started taking a stand for the way they would harass me regarding work. When I did, one of my bosses said my behavior is not good and if it continues things wont work, which was indeed a warning of firing me. So I decided to leave and I quit. now they say I have to comply by a notice period which was never drafted in the first place or they will not provide me with my salary. salary for the month of April, which I already worked for. I am due to receive Rs.X for the month and you know how this pandemic has messed with us and I am really having issues. also they say that they will give * months worth of salary at the end of June. since you know they have not provided me with any kind of legal agreement, I also have no assurance of receiving my salary of * months on june and how do I spend these three months with a pay.... Please help me out with my situation.... I can even send you a recording of the conversation I had with him this morning, so you can understand the intentions of my boss.