Money refund from skillshare

What do I have to do to refund the money from skillshare I have been charged since March of this year and I noticed this October. I never used their service, I had to block my creditcard and to use Netflix I entered details of another credit card but I am not sure if I will not be charged by skillshare since I found out that to cancel their services I have to log in my skillshare profile. I can’t find on my iPhone where I can see my automatic payments like Netflix.