Unrelated to the above but another no show question.

Just flew FRA-YYC and my TA booked a return ticket, so I have an orphan YYC-FRA segmented booked for 2 weeks from now.

I will need to go back to Europe at some point in the next 3 months but route and dates are unknown. Can I call AC cancel the second segment of this flight and use the credit in the future? Or because I started the itin I need to finish it?