Being charged ridiculous amounts without any explanation

I am moving out of my complex month end and going to another that doesn't use this company for their water and lights!!!!!! In two days it jumps to R400 then goes down to 360 then up to 390 all while no one is in the house!!!! I ask them countless to provide me with evidence of how I used R400 worth of water and lights in two days and they couldn't! Instead they tell me of 24 day averages! When I download the readings, those two days, and many other, are missing. This is a nonsense company I tell you.