I called back number (613) 714-9947 reached voice mail but did not say for what company.

Caller: (613) 714-9947

@John
"an internet search seems to link it to the CRA"

Only at first glance. If you read the sub text on that listing, it's there because the area code and prefix match, but not the last 4 numbers.

Caller: 1 (613) 714-9947

It's your cab calling to tell you it has arrived. At least, that was my experience with this number. If you try to call it, it just tells you to check the number and try again, so it's outgoing only. Oddly, I was getting IN the cab when the call from this number came, so I didn't answer. Sometimes it's not timed properly but, there you have it... Your cab's here!

Caller: (613) 714-9947

I do not know this number. although an internet search seems to link it to the CRA.

I did not answer it and no message was left

I called back number (613) 714-9947 rang once then goes to busy tone.