I have a contract with Cell C Pathetic Service

I have a contract with Cell C i get 1 gig data a month 500mb daytime and 500mb nighttime data i recieved my data yesterday and this morning i try go on internet not only did i loose my daytime data when i went on FB once but this morning i check my airtime because i cant do anything and what do you know i lost my night time data aswell i wasnt even on internet through the night so how can i loose all that data. i am so angry i call customer service and they cant help me i speak to technical sales they cant help me all i was told is i made a transaction in course of afternoon but the time they stipulating i was driving home so what is actually going on. no one can explain to me where my data is going. i will not pay another cent for this contract until the matter is resolved or better yet cancel this contract. i have never had so many problems with other networks like i am having now. someone better sort this out because i wont pay for a cellphone where my data is going missing the same day its loaded.