Double-charged by an app BoldVoice (Web Stripe + App Store) - How do I get a refund?

I’m looking for some advice on how to handle a duplicate subscription charge. I recently signed up for an app called BoldVoice. I initially paid for the annual plan on their website using Stripe.

However, when I downloaded the actual app to start using it, the app didn't recognize my web subscription and immediately prompted me to subscribe via the Apple App Store. I ended up getting charged a second time for the exact same service.

It feels like this is designed on purpose to trap users into paying twice, as the app and the website clearly aren't communicating.

Has anyone else dealt with this kind of double-billing trap from third-party developers? To get my money back, should I be requesting the refund through Apple's "Report a Problem" page, or do I have to fight with the developer directly to reverse the Stripe charge?