I just received the same call. I received no such letter also. I work in privacy area and they do not use robo calls as that. If it happens again I may call and ask them to provide me with my SIN number as if they are CRA they would have that on the file. I have been selected on a random audit in the past and the letter comes registered mail.
They have done audit on income tax returns for a few years and found some discrepancies. Requiring urgent action or legal action would be taken. stated they had mailed me info letter which I never rectived. I requested another letter be sent. she had my proper name and address , said she would mail a letter, then hung up.
I just received the same call. I received no such letter also. I work in privacy area and they do not use robo calls as that. If it happens again I may call and ask them to provide me with my SIN number as if they are CRA they would have that on the file. I have been selected on a random audit in the past and the letter comes registered mail.