Citi Finance/kotak Bank — Loan recovery scammers

I thought I was alone, after looking all these complaints I am really worried about the people really suffering a lot due to this mental stress. My mother is a government employee, she took a loan in Citi financial consumer india Ltd in 2007 and in 2009 the bank was closed and lifted from my town. she don’t know where to pay the remaining EMI’S, after 13 long years an advocate named prabhakaran from Chennai called my mothers higher officer and told that my mother will be arrested and it is a non bailable arrest warrant because of not paying the loan amount, and also told that give his mobile number to my mom and tell her to make a call. Officer made a call to my mother and explained the situation in detail, he also told that no such notice has been received, but just a call. After listening to all this my mother started crying because she did 28 years of service to the government and never received such calls from anyone. after making call to the advocate, he is threatening my mother that she will loose her job and will be in jail for making fraud.She got harassed by the advocate prabhakaran to pay the loan with no proper documents and directly they are insisting to pay for an account number in kotak mahindra bank. which we have no idea how to tackle the situation. From 2009 we haven’t received any calls or notice from the bank but all of a sudden I don’t know where there are getting the mobile numbers of the present officers.if they really want to recovery the money they should call my mother first, she is using the same mobile number from 15 years.
I request you people to please help me what to do next? Is it a scam ? Did Kotak really take over Citi financial