Left a vague MSG saying to return the call immediately and if I didn't, there was a vague threat. Computerized voice. Pretty creepy.

got a call from 613-209-0435. First part of call sounded intentionally cut off then the message goes into a threatening position to call or face potentially harmful consequences. It was a computerized or synthesized message.

ALERT - FRAUD - ALERT
Hey everyone, just been through a potential fraud SCAM. Someone called me, on my cell, and left a message that they were from the CRA. I called back and a guy with a thick "African" accent "trying" to speak English started bullying me into submission trying to say that there was a problem with my tax filing and that he was sending cops to arrest me. Mind you, I was only on my second coffee and still a little foggy at the time so it took me a minute to clue into this guy. So, as he attempts to lure me into giving him personal information, I google the # he is calling from and see this is a scam. I come back to the phone and let it play out. He asked for my accountant's name & #. I gave him a fake name and my old company's #. He pretended to call and speak to my so called fake accountant and when he returned to speak to me, he told me that my accountant admitted to filing the taxes wrong and now I had a $6000 tax bill to pay or face jail time. 10 years to be exact. So, I played along still and pretended to be horrified. I asked him if I could avoid all this by paying the amount up front right now...to which he agreed (probably shaking his head at me thinking how easy this had been). He proceeded to give me an email address eli@CRAcrimeinvestigation.ca and asked me to do a simple transfer to this email address. Once I could almost hear a smile in his voice and knew he had come to the end of his scam story, I unleashed the "WRATH OF KLAUDE" on him and tore him a new "a-hole". He hung up on me after about 2 min so I really didn't get much out of my system so I decided to call the # back and give him some more...he hung up again and when I called back the 3rd time, it was an answering machine...where I got to complete my full and total delivery of the venom I was carrying.
The phone # he called from was 1-613-209-0435.
I will be calling it on a daily basis to unleash my inner demons on these people.
I suggest we all do the same and keep this number handy for when we need to let some bad doodoo out of our selves.
Just so you know peeps, NO ONE AT CRA will EVER call you and threaten you in this way. This is a government agency and although they ARE pretty tough to deal with, they have rules and no one can be arrested for tax evasion until they go through due process.
So, note the ph# down, say there is someone at the door, come back and tell them you have to go cause the cops have arrived to take you away to jail  ;)
I have reported this incident at the Canadian Anti-Fraud Center 1-888-495-8501 as well as entered this info on antifraudcenter.ca
Have you got any pent up anger you need to get rid of today? If so, please call 1-613-209-0435 and let it out and share your outcome here. Or better yet, call that #, pretend you are returning their CRA call, let them take you through their whole storyline and then, when the money part comes up, ooops, tell them the cops are at the door and you gotta go ;D Let's waste these people's time for a change!

That I was to return his call as soon as possible or I would endure the consequences....

I received a call to today 1st of may 2017. Same story as above. I called back he asked my name and then hung up. At that point I became suspicious and googled this number. After reading your story I called him back and gave him good talking.