Paying for a promethease.com report follows these steps
- user uploads raw data.
- promethease verifies that the file format is understood
- promethease requests a $5 payment, and shows buttons that choose to pay via stripe.com
- user picks a payment method and approves the payment
- promethease prompts for a name for the job and an email
- report is generated for ~10 minutes
- a link to the report is emailed to the user
- payment is charged
So when the you supply credit card details you are approving the payment.
The actual charge only happens after delivering a report.
If you interrupt the process after approving payment, you can trust that you will not be charged. Otherwise the approval will timeout after 1 week. It seems that this may appear on your card immediately after approval, but will appear as a credit or cancellation approximately 1 week later.