Login failed for VAF userid error

I have been trying to schedule an appointment to submit my application to VFS South Africa. But I kept on getting a page which says login failed for VAF userid. I have already done online payment and the payment is already reflecting. I did write emails to their help desk several times but all their replies were not able to solve the problem. Firstly they said I must close all the website browsers relating to their site and use an updated version if internet explorer or fire fox and login again after an hour or so. I had to wait for 2 working days to get a reply. I did what they syggested. I actually log in again after 5 hours, but I still got the same error page. I emailed them again explaining that their suggestion wasn't solving the problem . You know you have to wait for 2 working days before you get your reply. I got another reply after 2 days telling me to use another device. I have already used different devices thinking that it might work. But the same page with the same error message is still coming up. I have rep**** again telling them their suggestion didnt work. Look, I have to wait again for 2 working days before I get any reply. Its now 9 days since I have been complaining about this issue without any solution to my problem. I don't know how much longer am I going to wait until I get proper help.