"Reconsideration" misconception
It seems folks think requesting a reconsideration is a silver bullet because they heard of one or two success stories come out of it. But please understand the hard fact about "reconsiderations": they are not an official process, and IRCC is not obligated to even reply to the request.
The correct channels in case of a refusal are to reapply (with a restoration if needed) if you are eligible but were rightly refused in your first application, or apply for leave and judicial review if an error was made on IRCC's side in fact or law in assessing your application.
To the first point, being correctly refused due to a mistake on the applicant's side. Please, do not waste your or IRCC's time to request a reconsideration. Just accept that you made a mistake and reapply if eligible.
To the second point, an error made on IRCC's side, this is what gets people. It's unfair that a wrongly-assessed application is refused. And the applicant shouldn't have to make the effort and spend the money on their side to submit a new application or apply for leave and JR to correct it. But those are the official avenues IRCC offers. You can submit a webform inquiry to request a reconsideration, proving that the error was not on your side, in addition to reapplying or considering JR. But you should not rely on a reconsideration alone as a viable solution.