Indeed I am. That's the form I used to make the ticket request, and on which I included my credit card number and signature. The confirmation I quoted above resulted from said ticket request. The payment terms in section 3 are a little confusing since it talks about making payment within 21 days, but my understanding (reinforced by soitgoes' confirmation) is that my credit card will be billed for the full amount on or before that date (thus constituting the payment in full referred to) and there's no need for me to try to somehow otherwise make a different payment by May 21.