What happened to the free trial? When you first sign up for Apple Music you get a 90 days free trial which you can cancel any time. If you've actually paid the subscription the process is the same:
https://support.apple.com/HT204939
As you should have had the free trial to decide whether you liked it or not you aren't really due for a refund. Strictly speaking all purchases are final: please see this page for information on requesting a refund:
https://support.apple.com/HT204084
Apple do say in that page, 'You can't request refunds for recurring charges':
however they have been known to be sympathetic in cases of actual error, so
it's possible that they may allow you a refund as a one-off concession:
but please be aware that they are under no obligation to do so: go to
https://www.apple.com/emea/support/itunes/contact.html
Alternatively go to the page
suggested in the Help page linked to above:
https://reportaproblem.apple.com/?s=6