I found the email respond that I rec'd, here it is:
Link on our website to request a credit exchange from your old ticket to your new ticket:
https://aircanadarefunds.business.xe...Refunds/Create
For your selections in each box use;
Customer type - passenger
Choose the option which best describes your service-related request - other
Choose the option which best describes your refund request - my option is not listed
and the important one;(add the check mark)
Application to apply a credit
I have an existing credit (ticket/voucher) and wish to use that credit as payment towards a new ticket.
whatever else you need to add can be put into the "Explain box" at the bottom of the page.
Hope that helps,
xxxxx xxxxx
Customer Relations
Executive Centre
Hope this help.