Change of Booking venue

I urgently need assistance to change my Driver's Licence renewal appointment booking. This request is extremely time sensitive so if someone / anyone from the RTMC can contact me back as soon as possible that would be great. There is no answer on ***, which I have been calling non stop since 9am (it's now 10:30) on Tuesday 30 April 2019 the number just rings constantly. I have also sent an email to ********** and desperately await response, I fear that the email medium might be too slow to address my requirement.