I WANT MY DATA BACK!

So I've been with cell c for years now, currently having 3 contracts. I have a data only contract, whereby i get 10 GB anytime and 10GB night, now for December and January month, my data depleted faster than i can't even explain how. I called cell c customer care and was told that the matter will be investigated, and i will receive a phone call after the investigation is done. To my surprise i received a call, but due to loadshedding our call was disconnected, no one tried calling back since then. I do not use data that much as I'm also connecting to my home wifi after hours. I cannot even utilize my night data due to poor connection, I'm paying cell c every month for utter nonsense!