Youtube Premium Double Charged

Hi, I just found I had 2 active membership with Youtube Premium. Both of them are exactly the same. I contact Youtube customer service and they said they can't help because it's billed through iTunes.

I called apple's customer service and was redirect to https://reportaproblem.apple.com/ to request for a refund. But that only allows me to request refund for a month. I was double billed for at least 6 months. Can someone help me with the double charge issues? thanks.