I have been fortunate enough to have my suit bag returned by the flight attendant when my AC flight landed in Edmonton. I had it stored in the J class coat rack but forgot to pick it up on the way off the plane. I realized when I got home and quickly phoned the Edmonton Airport information line. To my amazement, she already knew who I was and described my suit bag when I phoned. She told me the AC flight attendant found it and left it at AC lugggage services but the amazing thing is this kind employee also walked by the information counter at the airport and told the receptionist about my lost suit bag. When I phoned she knew right away where it was and saved me the trouble of going through the trace system. I was so pleased by this person's extra effort I wrote a letter to AC to thank her for the help. I think all the stars were aligned right that evening for me to get my suit back so quickly.
Keep calling them and it could well still show up.