Air Canada Reservation contact phone numbers

Web Assistance
In Canada or U.S.
1-888-247-2262 (toll free)
1-514-393-3333 (regular toll charges apply)

Hearing Impaired (TTY) Reservations
1-800-361-8071 (Canada/U.S., toll free)

Meeting & Convention Reservations
1-800-361-7585 (toll free)

Group Reservations (10 or more)
(No service fees) Canada: 1-888-567-4160 (toll free)
U.S.: 1-800-268-0024 (toll free)

From all other countries
Africa Europe
Asia Latin America
Australasia Middle East
The Caribbean 

Service fee:
A service fee applies for initial bookings or processing changes that could have otherwise been completed online. The service fee is $25 CAD ($24 USD) per passenger, with a maximum fee per booking of $100 CAD ($95 USD).

Link
http://www.aircanada.com/en/customercare/index.html