Today I tried several times to obtain a reward ticket on Air Canada using my DM miles.
Each time I was basically told that I can only redeem them on United flights.
If I'm supposed to be able to book a ticket on AC using DM then no-one at US or DM knows it's possible or allowed.
Please tell me what phone number to call and how to navigate the "press this for that" tree to get to someone who can perform the ticket reservation.