Impact meters bills black people more for electricity

I reside in Pretoria East, and I did not have electricity for a week in the July. I just received the electricity bill for the sum of R930. I leave alone and I use a gas heater and gas cooker most times. The bill does not make sense. I feel like impact meters bills according to racial profiling. I pay the same amount of money with my neighbors who leave with the children and spouses. Some are even pay less than me.