Got terminated from my job without valid reason. Should I return laptop, 4months after termination?

Hello Everyone, I was working in an Edu-Tech company where I got terminated 15days after probation period. In which according to company policies I have to serve notice-period for 2 months if I were to leave the company after probation period. But company terminated me without any warning and prior information which is illegal. 15days before termination, myself and my family was affected by COVID-19.There is a policy of 14days paid leave in our company. I submitted my COVID Positive report on JAN18-22 and applied for leave. But a HR named Megha bala approved the leave from JAN15-22 to only 7days not 14days. where on the day of applying for COVID leave itself my 4days recovery leave is been over. When I questioned this through the phone-call she replied rudely, ''I can talk only from the company's side'' I complained the higher officials and company owner through the mail mentioning her words. I was approved 14days paid leave. Rejoining after 15days from COVID recovery, there was a meeting set up with another HR and they told me they are terminating me immediately for low productivity for 3days before my COVID leave. I justified my side saying ''I've made a sale for the company, and there was No-Warning mail for my low productivity ! and why my other team members even more low productivity than me is not included in this meeting?'' they replied this is not about comparison! I asked the HR, let me serve the notice period where I'll look for another Job. They did not agree. I said let me resign, I don't want to be terminated. They agreed and also agreed to pay my salary pending dues. 1 week later that same HR threat me, ''we cant release the pay, we can just relieve you without Black-Listing you'' I did not react because I was having the company's laptop with me. I thought when they ping me for return of laptop I can negotiate about the pending salary dues. 4months later the Admin phone-called me for the return of laptop. I faced a huge depression searching for job for 4 months. Can I ask 2 months notice period salary for the return of company laptop and phone/ should I file a complaint for the illegal termination without proper notice and reason on Labour court including the HR for ill-talking on the time of COVID? Can someone help me, what am I supposed to do? Thanks in Advance,