Well, looked at Gate1.ca website and tried to some dummy bookings. TBH, that site screams "STAY AWAY" at every single step. And finally after looking at the T&Cs... a lot of their clauses are very sketchy, e.g. "8.5 Most of the low-cost carriers do not give refunds when you cancel your flight ticket. But it is possible to change the ticket with payment of costs and any price difference. You yourself are responsible for changing this ticket directly with the airline."

No airline, not even a LCC will touch a ticket issued by a (O)TA. Being the interface between the customer and the airline, that's what the (O)TA get's paid for. Pushing out such a responsibility.... speaks a lot about this OTA.

nevillek, you eded up with one of the (real) bad apples of OTAs. Next time, at least book with a respectable (O)TA, or better directly with the airline even if that might be a bit more expensive.