Do I need a visitors visa to visit canada from the Uk for 3 months?
Purely as a visitor to Canada (I’m assuming you’re a British citizen), you don’t need a visa. You do to work and as you know there is the “Work Canada” programme. I’d check what BUNAC said with the Canadian High Commission just to be sure. If you want to change your flight date, how much it costs and whether you can do it at all depends on the conditions of your ticket. If you don’t catch a flight you’ve booked on, there is no penalty except that you lose the fare because you didn’t use it. If you have a flight ticket you don’t want to use, you can apply for a full or partial refund if the conditions of the ticket allow it (if it’s not the full scheduled fare you often can’t).