I don't see AC has a specific form for SQM discrepancy. I only got 50% Miles as SQM with a Flex Economy ticket, operated by UA though. Looks like I will need to try the Customer Service Form.
With this being your first post, welcome to FT. But note that flights operated by other carriers credit based on the earning rate for that carrier. It doesn't matter whether you bought the ticket from AC or what fare brand you bought. Please see
this thread for more details, but the bottom line is that you were likely credited the correct mileage.