Air Canada delayed and bumped
 

My wife was flying from Calgary to Orlando with a stop-over in Toronto. Checked in online the day before for both flights and had assigned seats.

• First flight was delayed in Calgary by 1.5 hours due to technical issues
• Arrived in Toronto late, but made it through security and US Customs to the gate 20/25 minutes before take-off
• Flight was just starting to board
• Went to board and was advised that her seat had been given away
• Given a $10 voucher for meal
• After contacting our travel agent (ticket booked through my corporate travel agency) and much discussion at gate was advised she might get on next flight 3 hours later
• Waited at gate for next flight and found out 20 minutes before flight that she had a seat

Our travel agent filed a complaint but has been stone-walled by Air Canada's customer support. They are claiming "there are cut off times to all flights which is why she was not allowed to board her original flight."

They also claim that "As there was not sufficient time to connect per regulations you were automatically re-booked on the next available flight." This is just out and out not true.

Any advice on next steps?