Unhappy consumer

Please advise me of my rights as a consumer. over the past 2-months my Electricity bill has doubled to tripled in charges for no explanation When i ask the company that reads the metre iam told i should pay for them to come and prove to me that they indeed read my metre and that their system is working and that these are my true consumption expenses. I used to pay between R900-R1,400 - My July August bill is R3,326.10. Please advise if there is anything you can help me with.