Is It Fair for HR to Withhold My Relieving Letter Over Alleged Misbehavior? Seeking Advice

My last day at my current organization has been completed, and I received a call from the HR separation team alleging that I misbehaved with HR over the phone by using abusive language. They are requesting an apology email, or else they will not provide me with the relieving letter. Is this situation possible? The HR team was also rude. Please advise.

Questions to Consider

One question is, did you misbehave or shout at/abuse them? If not, why would someone make such a claim? You need to give us the proper background.

Secondly, do you really have much of a choice?

Apology and Its Implications

Third question, even if you were to give an apology, what is the problem with that? What are you afraid of?

Apology Letter and Relieving Letter

You require the relieving letter more than the HR needs the apology letter. You also admit you raised your voice when dealing with HR (perhaps in a fit of anger or annoyance). I suggest you give an apology letter for raising your voice with HR, complete the formalities, and move on with your life. Don't make the apology letter an ego issue because from the limited facts you shared, you were not completely blameless even if you were provoked by HR.

Best Wishes

Thank you for your suggestions. I have called HR and explained the situation. I apologized for raising my voice. She proactively understood and accepted it. Problem solved.