I have been charged for the Apple Music but it is suppose to be a 3 month trial

We are fellow users, we obviously won't know what you have or haven't been charged for.

If it is an actual charge that shows on the iTunes account's purchase history and isn't just a : About payment card authorization holds from the App Store or iTunes Store - Apple Support

contact iTunes Support : http://www.apple.com/support/itunes/ww (click on your country's flag, the country where you live, and which is therefore the country on the account ; click on Contact Support towards the top right ; click on Get Help under 'Talk To Us’)

You must have already used the trial in the past, like any new member offer for any service it is just a one time deal. Rejoining as a previous member will charge for renewal.

This is a user to user forum I am afraid. If you need help from Apple with something in your account you want to go to http://reportaproblem.apple.com or http://getsupport.apple.com