A lot of negative comments from people here, but I have to ask, have you used Apple Music and has this feature failed you? I didn't have any problems myself (not a huge collection, but it worked well for 24GB of songs).

Some people have mentioned that it can be easy to fool the system and gain free songs, but paying $9/month for Apple Music gives you access to every song either online or offline and you can add them to your library.

iTunes Match however is a different thing and they likely have to be almost sure the song you have is the song you should get access to from the iTunes Store.