Hi, yes so you need to download an app called TextNow on your windows system, though it is available for android and ios but the desktop version for windows seems to work pretty well for me.
You can select any free canadian phone number from the app and call the ircc helpline "1-888-242-2100". (8am to 4pm Monday-Saturday)
I called at around 10pm IST and initially the IVR picks up and starts giving a lot of information and in between will ask you to select options depending on your query and application type.
The sequence of options that I went through on the IVR was "1, 1, 1, 2, 2, 2" and then I guess it is press 9 to speak to an agent at the end.
You need to keep all your application details ready when you call.