Reg: Filing a Defamation Case

Dear Sir/Madam, My dad sold a property to a buyer and legally everything is fine. The property was bought by buyer from bank loan. As you know if any kind of legal issues exits he could not have sold the property. There is some issues with association and my dad as they have billed for which we did not avail the service. In this regard my dad already sent an official email communication to flat association and updated now i have sold the house to new buyer and the new buyer is not liable to association for any pending charges. Lets discuss and resolve the issue. Please note i'm no where in the picture of this deal, i do not know who the buyer is and never contacted him via phone/email/sms at any point of time. Now the new buyer got my number somehow and disturbing me and asking me to tell to my father instead of contacting him directly. I'm receiving multiple calls from different numbers and asking for update whether did you inform your father or not. I'm nowhere part of the deal, i do not know what are the terms and conditions and what is the commitment given. Can i file a Defamation Case against that person which is responsible for making calls and disturbing me and not allowing me to work. Irrespective of the time he or some other unknown person is calling me.