Europcar Technical Issues on Website/App

I've made a booking with Europcar using Kulula. After the booking it directed me to http://www.ready-2-go.co.za/#/reservation to update my reservation details. However, I get technical errors on all browsers on several PCs so I cannot update my booking. "An unknown error has occured"

I phoned the call centre. I was transferred 4 times before someone gave me the number of someone who may be able to assist me. However, it is a mobile number and I am uncomfortable phoning an employee on his/her mobile number.

Furthermore, I installed the app, and twice I have tried to register my new account and I get an error there too. "Ooops A technical error occurred, please try again later"

This is appaling if you want me as a client. Expect me to cancel my booking and go with a different company.