What you have received is not ADR, it is a procedural fairness letter. IRCC is not concerned about your designation or the promotion you received, all they are saying is that your job duties listed in your work reference letter do not match with the job duties for the NOC selected.
Section 75 of IRPA states:
You do not need any affidavits or clarification for your job. That is established from your work reference letters, what is missing is that your job duties do not substantially match that of the NOC.
If you filed your application though consultant, they it was their responsibility to ensure that your NOC matches your job duties, and if they messed up, then you should talk to them as no due diligence was done before sending filing your application.
At this juncture if your send a new work reference letter with a new set of job duties, you will have to show what were they missing before. Since this is a factual scenario and you have to draft a very strong letter to respond to the PFL.