Broken?

So I downloaded this app hoping it would work and it doesn’t... It first told me I needed more coins so I first purchased 30 coins (or $4.99) but apparently that wasn’t enough so I just bought the unlimited version ($19.99) and instead I got a “request failed: bad request (400)” So I was hoping I could get refunded or have the app fixed.

Victor Arias about Snap Save & Upload - Quick Edit Snaps & Stories, v1.1.0