Stss prepaid metering worst service ever.

Stss prepaid metering system charged us R30 in 20 seconds for electricity our electricity bill is being charged with various high amounts when there is nobody at home during the day. Tried phoning them they put me through to the Finance department which I still haven't spoke to till today, not answering their calls just ons hold the whole day. On the 27th of February we were charged R49.91 for electricity never ever have I paid more than R25.00. An adjustment has been app**** to our account which indicates the incorrect Unit number. Once again our electricity today is over R30 whislt nobody was at home. Nobody is contacting me back. Can someone please assist me from Stss and not revert to an email which never gets responded to or not phoned back?