This is the correct number. I've called cic thrice on this same number from the US. When the call volume increases seems like they shut it off. So keep trying. My experience was good when I called early morning like 8 ESTDid you try calling them at +1 (613) 944-4000 from USA? I have tried many times this number and it routes you to IRCC and then it says you cannot reach to this number from outside Canada.