Over charging credit card

I bought a ticket using this app and got charged twice. Refund still pending. Problem is app cant handle a transaction. I bought the ticket and included premier access. The ticket went through but not premier boarding. The app reported failure and to try again. The app should report that the ticket is good but premier boarding failed. The error message is to fast and there is no way to view it, it just disappears. So, the error message lead me to try again and I bought a second ticket. Its a dumb app without any consumer protections.

Rob.hates.this.app about United Airlines, v2.1.13