As an experienced e-commerce professional, I understand the urgency and importance of resolving your payment issue on Shopify. I have a proven ability to troubleshoot and resolve complex issues promptly, which is absolutely crucial in this situation. Having managed Affiliate Sites, Wireframes and Designs through WordPress, I've gained a substantial understanding of HTML and the Shopify Platform. This means I can swiftly identify any coding tweaks that might be necessary to fix your payment processing problem.
My expertise doesn't just end with troubleshooting an issue; I am also deeply familiar with various payment gateways and their integration into Shopify. In addition to Shopify management, my skill set includes Digital Marketing Reinforced by strong SEO Writing Skills. So not only will I be able to diagnose why transactions are failing, but also ensure your online store's optimal functionality--improving traffic, visibility, and sales.
Above all else, my commitment is towards client satisfaction. This binds well with your need for prompt service, since the longer the payments error persists, the more it negatively affects your sales. Let me bring my 6+ years of diverse e-commerce experience to bear on solving this problem quickly and competently for you!