Cell C data rates are not cheap

I just recently ported to Cell C, as I was with MTN, I have come to realise that even though people say that Cell C data rates are less priced yes I agree with them but I've also realise that with the same phone, same apps. My data no longer lasts like when I was with MTN. With MTN I used to buy 2GB data n they would last for a month n few days n with Cell C they don't last at all. I even asked a guy I know and he also confirmed that he also experience the same issue. Even if I switch off data sometimes during the day and at night still they don't last like I was still with MTN. I've moved from MTN cos of their network problems n I'll now move from Cell C for the data issue. I now need to cancel my contract...