Vodacom no customer service

I buy 100mb data bundles from vodacom each month, last month when trying to buy i kept getting the message "Not done" the next day i got charged for 3x 100mb data which is R29 for each one. so i had 300mb which i couldn't use up because it was to much . this month when i bought my 100mb bundle, i only received 55mb while being charged for 100mb :( tried to report it on vodacom website and calling 082135 without success. i dont want to buy again for two reasons, because i was cheated and because i dont want to get cheated again . VODACOM has terrible customer service i am considering changing to another network