Overcharging, never credited despite assurances

In january (***) my account came as R 3172.36. usually its just R 1000.00 approx. I called in. they said they would rebil it for me. I got an SMS to say it had been rebilled. In Feb, I received another invoice, that was still r 3172.36 outstanding. I had no choice buy to pay it or they would cut my electricity. But...on calling, Ref no: ***, I was told that a credit would be passed for R 1300.00 on my next bill, but I should take a photo (the box is locked) of the meter and send it to them. Come March....I now owe R 2994.57. It IMPOSSIBLE that I owe so much. I use very little electricity, and am a normal, average working woman, who just affords R 1000.00 a month on electricity. I cannot afford to pay R 3000.00 a month, and Eskom is ripping me off. I have spoken to so many people already and all of them assure me that a credit will be passed, and yet nothing happens. I dont know which way to turn anymore. Please help.