City of Johannesburg double billing and no correction for over 6 months

I have transferred my electricity to prepaid since August 2019. I am still billed by the municipality as if i’m still utilising traditional electricity on a monthly basis. I went to the municipality since November 2019 to resolve this issue with no success. I am literally at the City of Johannesburg offices in Waterfall every other weekend, no one is taking accountability for this matter. It’s frustrating as I have to pay double for their inefficiencies.