Frustrated by vodacom

Yesterday I loaded 100mb data and in seconds it was all gone I checked my settings and it was the same as always so I loaded a other 100 mb and the samething happens so i call vodacom and what I knew would happen happens but tried anyway they tell me my internet used it but I wasn't on the internet by the end of the night i had lost close to 250mb data and R29 airtime and this is not the 1st time this has happened and vodacom just say the internet used it