VFS Global Schengen Visa Appointment Complaint

As part of our plans for the Eid al-Adha holiday, I've been attempting to book a Schengen appointment for my flight to Marseille on June 15th since March, but unfortunately, I haven't been successful. Although I have a Schengen visa from France that is still valid for two years, it will expire on June 14th. It's frustrating how often there are no appointments to be found, and even when they do appear, system errors always seem to get in the way of me securing one. I've encountered a frustrating situation where, despite my best efforts, the system failed to process my payment at the final stage of multiple appointment attempts. As a result, I was unable to complete the appointment as planned. I'm feeling frustrated and discouraged by my inability to secure an appointment and I'm struggling to find a solution. I've already taken care of all my hotel and flight arrangements, but I'm really worried about my visa renewal. If it doesn't go through, I'll be facing a huge financial setback. It's really stressing me out :((( I would appreciate the assistance of VFS Global regarding this issue.