Vodacom real thefs

I do not onow if it is me or I can be wrong about the following every time I load data it is as if vodacom steels the data that I am using or it can because I complainde about there bad service,that is why when my contract ends in september I will switch it over to pays as you go the reason for that is simple I pay 700 rand a month on my contract and I only get 500 megs data,350 min and 100 sms and when my data is finished in week or 4 days I have to load data again and the prices for vodacom data is a joke and what you pay for it and then I would get a call from a vodacom consultant asking me if I would be intrestef in paying another 250 rand for data then I would decline because I know at end of the month I would pay more then just 700 rand then I will pay 1000 rand so in short vodacom thank you for you GREAT SERVICE