RTA ROAD TEST BOOKING UNLIMITED

I can't book it through the website or the app, it says that I need to make a payment even though I paid full upfront for the unlimited option in dubai driving center. It would be more convenient for me to book it through the website since I can select the date and time rather than getting a random one from rta once ddc sends them a request. I tried contacting them but I keep talking to the AI with no way to talk to an agent.