Robbing my data

I put data on my phone twice which usually I use up in a week or two, when I put data on my phone without even chatting to anyone the next day it is finished the second day I put data on my phone in the evening my data was off until the morning and the data was gone. During the day my data is off because I am on my works wifi

When it is time to upgrade I will terminate my contracts because Vodacom is *****ing. we pay every month the contract but you guys rob us people who tries and support you.