Nobody on here can potentially refund anything, we are fellow users and these are user forums. When did you cancel the subscription ? If less than 24 hours prior to its auto-renewal you are likely to be charged. If more than 24 hours try contacting iTunes Support and see what they say e.g. via the account's purchase history, the emailed receipt, or the 'contact Support' link at the top right of every page on here
Apple Event: May 7th at 7 am PT