Bad service

VERYY BAD SERVICE. I ordered with Takealot and my order was cancelled, I was refunded on my payflex account and now I can’t use or withdraw the money in my wallet because I have changed my number. I have beeen trying to change my number since last week sending countless emails but I am not receiving any response. I have been calling the customer service centre everyday but the call cuts because of high call volumes. The webchat has been of no assistance as well as WhatsApp. I need to change my number urgently.