Error in form when trying to process transactions

A customer got an error when trying to pay with Amex on the form. He tried twice. What do I need to do to fix it?

I added a subtitle to the heading and removed the background color, but those changes aren't being reflected on the page where I have it embedded. Why?

How can I remove the extra space around the form? See attached screenshot.

https://form.jotform.com/73414228884159

http://granfondotexas.org/advance-jersey-orders

We had an issue with our payment system earlier that has been resolved.  There should no longer be any errors with payment.  If there is, let us know the specific error and we will be happy to have a look.

As for the space at the top of the form, add the following code to reduce it:

https://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes

.supernova {
padding-top: 0 !important;
margin-top: -60px !important;
}

Adjust the highlighted value to further adjust the spacing.

Still not working. The same customer tried to make a payment using AMEX card and keeps getting an error message. 

Here's the form again: https://form.jotform.com/73414228884159

Thanks!

The Stripe forms are supposed to work properly.

Could you please provide us with the full error message?