I have been waiting since January 29th to get six credits refunded. I was waitlisted on a flight from Vancouver to Toronto and was not upgraded.
I sent the " Reporting an Eupgrade discrepancy" form in four times and called AC three times.
Of note, I never received an email confirmation when I submitted the request form...and I was supposed to, so that is an issue.
As for the calls, I used the Altitude line so was connected quickly. The first two times I hit "3" to speak with the agent responsible for " eupgrade requests and all other subjects." They simply told me I would have to wait for a reply to the written requests.
On the 3rd call I hit "2", which is the line for issues with the website. I got a helpful agent who eventually sent an escalation request. This was after her help desk told her that my upgrade request was marked as "cancelled" and no credits had been removed!! I had her go back and add and subtract my credit usage from January 2019 and she finally agreed that I was short six credits.
So back to her help desk again who advised her to tell me to send another discrepancy request and wait!! I politely said "no way" as I had done that three times so she then sent an escalation request.
We'll see what happens. I will report back.