Bookit.com is the agent for me in this case. 

I cancelled my flight and now have a useless voucher for the flight portion that expires by October 30th, 2020. This is a year from when I booked but my vacation was supposed to be this March break. 

Bookit.com told me that it is not in their policy to change this date set by WestJet.

WestJet gives Expedia customers 13 months from the date of travel to use the voucher. That is a significant difference.

Bookit.com is attempting to have WestJet offer a waiver to do this but they won't listen. Bookit.com has tried 

At this point, I risk sacrificing $3400 or if I do use it by October 30th I'll need to pay a $600 rebooking fee still that has NOT been waived.  The website is misleading people. A refund is cash back not a voucher.

Do the right thing here WestJet.