I agree with calling PTS but in this case, AC has caused the itinerary to fail so I would expect BD to ask AC to make some alternative provision available. It would help you if you were able to find an alternative means of getting to YYZ. If you really are travelling from a total backwater with only one daily flight to YYZ then there may not be much that AC or BD can do other than move one flight to the day before or move the other flight to the day after. Ye cannae change the laws o' physics, as a famous Canadian once said.