There electricity Billing is inflated

I moved in at the end of January this year. Every since then my electricty bill has been increasing by R200 each month from the prior month. I went from paying about R250 for electricity to paying R1150 in 9 months. This is not possible. They then installed prepaid electricity for us and said they would pro rata our electricity bill. And now they say in 2 weeks we utilised R1150 electricity. Is this possible? i don't think so. last month it was 900 and something. So yes they increased it by R200 again even though we got prepaid meters half way during the month! So i guess we are being ********** here