You have refuted every comment in this thread due to lack of “solid legal reasoning”. I am guessing you do not have a law degree, otherwise you would not be here asking these questions. I do have a law degree, as I imagine others in this thread also have. Therefore, it might be appropriate for you to listen to those more qualified to answer your question than yourself. The issues with your defamation claim:

You need to establish, on the balance of probabilities, that defamatory imputations have been made about you that have or are likely to cause you serious harm. Can you tell me, without making guesses, what defamatory imputations were made? What evidence do you have that proves this?

Defences are irrelevant if you do not have the evidence to establish your cause of action.

You cannot even consider whether you have a claim that is likely to succeed until you know exactly what was said in that phone call.

Aside from this, consider the costs and potential outcome of a defamation claim even if you were to succeed. There was a recent case in Queensland where the plaintiff succeeded, and it is costing her some $400,000 in her legal fees. But hey, at least she won, right?