Why do my data and wifi stay on together?

[AC Question]

why do my data and wifi stay on together?

I have a galaxy s2 and the data and wifi stay on at the same time. Its using all the data up on my plan. How do i fix this?

 

[B. Diddy]

Re: why do my data and wifi stay on together?

Welcome to Android Central! So when you have both wi-fi and mobile data turned on, the phone still seems to use your mobile data instead of the wi-fi? Does this happen on every wi-fi network? Are you certain the wi-fi networks are successfully connecting? If you turn off mobile data but keep wi-fi on, does it still connect to the web normally?