Unfortunately, in most cases, they won't be able to provide you with any information or answer any specific questions on processing if an application is under 21 months. Maybe, after 21 months you can send the request again, call them again, and ask your MP for assistance. I do realize this is not ideal (to wait for 21 months.) However, this is what the official IRCC website says.
Processing times will vary based on:
- the type of application submitted
- if the application is complete
- how quickly we expect to process applications we’ve already received
- how easily we can verify your information
- how long you take to respond to any requests or concerns
- other factors
More info here:
Apply for Canadian citizenship - Canada.ca
I also can't help but check the Google Sheet tracker to compare timelines and processing, application details etc. It is strange that some applications are processed quickly, while mine (and others who are waiting) are kind of stuck in limbo without any updates for a while.
As the saying goes - Patience is not the ability to wait, but the ability to keep a good attitude while waiting.