Travelling YYZ-Grand Cayman, February Saturday to Saturday.

Just learned by looking at the flight that they have changed it to Friday to Friday, since there is now no Saturday flight.

What are my options? We've booked a condo Saturday to Saturday, and if we can't change that, we are looking at additional cost for accomodation (3 rooms, 5 adults....)

3 of the adults are my kids and girlfriend, who are in university. For one, we have to change another booked Air Canada flight to get him in from Ottawa to YYZ the night before.

Thoughts etc before I call in?

Really annoyed!