If you blend different fare types in construction, then the whole ticket will fall into the most restrictive rule.
So the H fare YYZ-EZE is refundable (subject to a cancellation penalty). But when you tack on a Q fare from ORD to YYZ, the non-refundability of that segment kicks in, and covers the whole ticket.
Try doing a fare search on Expedia or Travelocity, then select the fare and book in that fashion.