Prank dial it is illegal in Canada ?

I'm not from Canada but it is a criminal offence in many countries to make a call just to cause alarm, annoyance or distress, using false information etc.

Canada still uses a lot of English law so it's probably the same as here - up to six months in prison per call:
http://www.legislation.gov.uk/ukpga/2003/21/section/127

(And remember it's what the person receiving the call perceives it to be that matters, not what you intend it as; a repeated joke to one person can be stalking or harassment to another).

He knows it's you meaning that you likely told him it was you. Maybe you should have never told him it was you. Also tell him to just suck it up and get over it.

Yes. Illegal.