Apple Music wrong charges = REFUND

I have had my Apple Music via my current mobile phone carrier for few years (Mobile phone service provider: TELSTRA - Australia), However, i've noticed since January 2018, Apple have been billing me for Apple Music as well as my mobile phone service provider (not just a tax invoice as i was lead to believe, but an actual charges to my credit card)!

I have not made any changes to my Apple Music subscription and i don't know what triggered this monthly fee of $11.99 AUD and why, but this is an incorrect charges i have been charged for the past 17 months from January 2018 till May 2019 (inclusive of May 2019). I would like an explanation how did this occur and what do you intend to do to resolve it promptly!

My Apple account details:

a(xxxxx)man@yahoo.com.au

Mobile phone number (linked to my Apple Music): +614xx xxx 006