Cell c robbing people

I have launched a complained with cell c about my data that disapear . Witinn 1 or 2 days . A lady from cell c called me and said she will come back to me that was a month ago . Sofar nobody came back to me and still my data is finished witin a few days . . I am using wifi at home so i cannot understand why my data is running out so fast . I dont think that i will be renewing my contract with cell c in January 2020 . It feels like they are *****ing from me . And i have been a client for more than 10 years . I cannot keep paying for data and dont get the benifit to use it .