I created a blank profile in Firefox without any add-ons and processed the payment that way.
Having received the notice respecting support for commercial modules I went to the provided URL and find that it simply will not accept any form of payment. I am using Firefox on a CentOS-6.7 workstation to connect. NoScript is installed but the site is temporarily white-listed when I visit. I left a message on the 'live' help message box. However, no-one was available and I have not received any further contact since. None of the messages I received give an email contact address and I cannot locate one on any of the web pages.
I find this all rather frustrating. I am quite willing to pay for the support but to obtain it I am forced to deal solely with a dysfunctional automated system that evidently provides no readily available means of contacting a real person.
I particularly find distasteful receiving email messages that provide absolutely no return address that will accept any questions or requests for clarifications. This is simply discourtesy.