It’s natural to just use QuickTime Services for everything, but you don’t have to. For one thing, historically, QuickTime will not recognize Windows Media files. See Flip4Mac:
Since importing raw data in Audacity only resulted in static, the issue could be that the file’s structure is broken. You might have better luck repairing it using a specialized tool. I found this guide that could help: https://news.mаcgasm.net/tips/repair-m4a-file/ . It provides methods for fixing corrupted m4a files, which could be exactly what you need. Another thing to try is opening the file in VLC Media Player to see if it can recognize any playable data. If VLC plays even part of the file, you could try converting it to another format. Also, some audio recovery tools are designed specifically for extracting data from damaged files