I was charged twice.

I was on tge stats.fm website, I paid 13.99 for the lifetime membership through stripe. I saw the payment go through on my bank app. (I get notified every time I make a credit card purchase) I was redirected to a page prompting me to download the app. I followed the link, but my purchase didn't show. The app was cluttered with ads and prompted me to buy the membership again. I looked into the FAQs and they said sometimes the app glitches, and to attempt to buy the membership again to verify the purchase. The payment this time defaulted to Google Pay and got deducted from my credit card again. It was a lower price due to and app sale, $9.94 as opposed to $14.99 (the standard in app cost). I just want a refund of the additional charge please.