Cell C
Unable to use the internet

I purchased a Samsung S4 but i find myself unable to browse the internet or stream videos in the Nagina (3604) and Pinetown (3610) areas. At times it does work but more often than not it doesnt. Usually after 5pm i can't even open Google search. There is plenty of signal but i don't understand why i cant browse. does the signal tower need upgrading? can someone not give me a story, all i want is a truthful explanation and results!!!