I receive a notice that I purchase a music subscription which I did not. I don't want to be charged for something I am not using. How do I unsubscribe?
Welcome to iMore! Your easiest resolution would be to check your subscriptions and cancel your Music subscription, if there is one. More info here: https://support.apple.com/en-us/HT202039
If you don't see the subscription then, just as @Highrisedrifter said, it's probably just a phishing scam.