Double Charged for Spotify Account

It recently came to my attention that for 55 months I have been double charged for my Spotify account. Back in 2015 when Spotify and Apple split, I transitioned my Spotify Prime billing over to Spotify because it cost me $10.91 whereas Apple charges $14.19. At this point in time, my Apple Spotify account was downgraded to a free “trial” account and I was no longer being charged the inflated premium. I’m only now realizing, 55 months down the road, that once that trial period ended, Apple began charging me for my account that had previously been canceled with them. They chalk this up to a “user agreement that states that once a trial subscription has ended, you will automatically be charged for the premium account”. I have never once received an email regarding these charges. The total charges for these 55 months amounts to $780.45. After 4 hours on chats and on the phone with Apple employees and supervisors, I was told I would be credited $28.38. I was never notified of these charges. Can ANYONE help me or connect me to the right representative who can right this wrong??