VFS Global On-line appointment bookings

Why does VFS Global make it so difficult to make an appointment online to apply for a visa??? They insist one books on-line but there system is NOT AT ALL user friendly , is it because they have the monopoly that they think they do not have to provide good client service. Every time I try and book an appointment I get the following message " Access denied Error code 1020 You do not have access to visa.vfsglobal.com. The site owner may have set restrictions that prevent you from accessing the site." If one telephones the office applicable to the type of visa you require you get a call-centre voice telling you how to apply online and yet there is always an error on their online booking system