Yes Bank — regn of my mobile no on phonepe account by an outside scamster!!!

Address:

600042

I live in chennai. On 11th sept at about 4 pm, i recd an sms on my mobile from phon pe source (No number seen) saying that i have sucessfully initiated the process of phon pe account on my device thro' ybl wpi app. I did not respond to the otp message. Obviously somebody stole my data and tried to sabotage my account. I immediately arranged to block my accounts in both banks to avoid any debit!!. How is it possible to initiate the money transfer process without my involvement with my device, on which i have not downloaded the app at all? What is the role of yes bank ltd (Ybl) in this affair? How can i get the unauthorised regn of my mobile no from the phon pe registry removed? Whom should i approach so that the scamster would not try again in such situations? Please advice. Revealing mobile no also seeme dangerous now a days. I am a senior citizen. Please respond with correct followup for me to adopt now!! My e mail id is [protected]@yahoo.com. Thanks