Experience letter not provided.

Hello, I worked in a software company around 1.5 year then I resigned. Company was giving me loyalty bonus + AMPB (Annual Monthly Performance Bonus) per month with my salary. After my resignation I served 2months notice period but company not providing me last three months salary *( including notice period ) and my experience letter. They are saying you haven't completed an year after your confirmation. Some points can ask to company.. 1. When I joined, why offer letter not provided to me? 2. You are saying deepak you don't have technical skills then why you haven't fired me? Why you haven't provided me any warning letter? 3. You are saying I haven't completed one year in company however I completed 1.5 year then where is agreement letter if you provided to me? 4. last time when I came back to home due to COVID9 you decided to deduct AMPB and Loyalty Bonus for employees those are not working from pune. This was the only one condition which messaged on slack group then why you not deducted for all employees those are not in Pune? Please help me.