Prepaid Electricity *******

There is something not right with the Meter Mate usage. I recently moved in to a new complex with this electricity meter. I am literally watching the units drop. From the time I switched off my washing machine, when it reflected as 53.8 units left, to now 20nminutes late and it is 51.3, with the units just dropping, when all I have switched on is my TV. I filled R500 on the 30th May, which converted to 186 units. I am not even halfway through the month and I am now down to 49.3 units. What is going on! This is such a *******. I need someone to come and check this meter!