F&F and Experience/Relieving letter pending

Hello, I am an HR professional and worked for a Delhi based company for more than two years. In my last 5-6 months they hired a new HR head who was also my reporting manager. It didn’t work out between us, she always targeted me and yelled at me for unnecessary things. I finally resigned, served my complete notice of 30 days and handed over all the data to my replacement. I returned my laptop with no data in it because all the data was already handed over and transferred plus it was confidential HR data so it could not have been shared with the IT team. After multiple follow ups on emails, calls and whatsapp, the HR Head replied after 40 days of my last working day blaming me for company data deletion and manipulation. I am now being asked to accept and apologise for the aforementioned only then will they close my F&F. There was no communication from them whatsoever from my last working day till like 40 days of leaving that org. She was copied and kept in loop throughout my handover process. I think she is only doing this out of whatever grudges she holds against me. I feel harassed. I had already looped in the founder and ceo of the company What are my rights? I have explained myself multiple times on emails. Can I use strong words like harassment on my response to them because I don’t think I owe an apology?