No response to electricity usage enquiry-CITY OF JOHANNESBURG

I'm on a prepaid meter for electricity. My electricity usage has increased over the past few months, this despite installing geyser timers and a making a concerted effort to cut back drastically on usage. I'm suspecting I'm being overcharged. My monthly statement does not reflect electricity due to being on prepaid. On 10 July I requested a detailed electricity statement for the past 12 months. Despite numerous follow up emails, I have had no response. I thought service delivery would be improved under DA rule. At least that was what was promised in their election campaign.