Trouble shoot and debug payment system between JVZoo, S2Member and Paypal

BACKGROUND I built a membership website on a Wordpress platform, using S2Member as the membership software. I am using JVZoo as my affiliate management software, which integrates with S2Member. SITUATION When I run a test sale, I am taken to the page that I have included as an attachment. The sale is automatically refunded and I am not taken to the membership page. I have the Logging Routines feature in S2Member turned on, so the error logs show what is going wrong. I've tried everything that I know how to do, but nothing has worked. REQUIREMENT I need a programmer who is efficient with JVZoo, S2Member, and Paypal integrations to troubleshoot the problem and find a solution. The 3 platforms are designed to work with each other, so there is no need to program anything, simply check over what I've done, find out where I went wrong, and show me how to fix it or go ahead and fix it yourself.