Incorrect Unfair billing for a pensioner

Account number ***. You can contact me at *** Overbilling on this account via rough estimate. Meter readings are never done but an amount of more than R1300.00 per month is billed for the past 3 years for a pensioner who stays alone and does not consume so much electricity. Can we get clarity how billing is done on this account asap. Electricity was switched off and a payment of R11678.15 was made in September. After all this the account in October is already sitting at R10391.81. How is this even possible?? Kindly advise how this billing is far as he does not have money to pay for this account that is incorrectly and unfairly billed. Can someone explain properly how billing is done for this particular account. Contact Ernest Mosadi