Poor websites for many years

I have an error "An error has occurred. Please contact Customer service." when trying to login and access my contract on mycontract.mtn.co.za

I have had a contract with MTN for many years and whenever I try to access any of their websites there have always problems. Even when one is able to access the site is difficult to understand and they seem unable to consolidate their offering into one site after many years of fiddling about. I think this is the last straw. MTN have been encouraging me to upgrade for several months and I am now interested, but Vodacom exhibits for more professionalism. It is very concerning when an organisation like MTN, a communications company, seems unable, over many years, to create a reliable, easy to understand and credible web presence.