Annual Increase

I signed up with them in March 2020 for a 20/20 Fibre connection. The advertised price was R745 per month. I got a notice that the price will be updated in July 2020 to R 863 per month. That is a 16% increase year on year. I have phoned customer service twice already and keep getting told that a manager will return my call. I haven't heard anything in over a week. Given the CPI increase for 2020 being in the order of 4 - 5 %, this increase is unfathomable and does not warrant moving to their network.