R1000 bill for appointment not kept?!

Had a dentist appointment scheduled for 11/12/2020 at the Glenfair branch. Found out that morning I was in direct contact the day before with a client who tested positive for Covid19. Contacted them and let them know I can't be at the appointment.

Now I'm being hounded for a R1000 bill for appointment not kept, which is ridiculous!! Been trying to get in direct contact with the dentist to discuss, but never get a call back.