Bulk deduction

These ones are overcharging us here at Greenbay eco estate. We get charged in bulks and when you query about it, they cannot explain why. I loaded R300 on Wednesday around 11/12 then did laundry. Just one load. Mind you, during the day I am at the office, I come back at home around 8pm. Today I am on minus (-)R217.48 when I call to ask about where are these charges coming from, they cannot really give answers instead they tell you about what was charged without telling us how were charges calculated