query on my data bundles

I upgraded to a new package with MTN in August with Neo Masilo. I am supposed to be getting 4GB of day data and 4GB night express however I have never received my full data as I am out of data before even reaching 4GB of data and I have to buy some data. I even activated data share for my children however they are unable to connect and I have removed them as I end up buying data for them I called MTN and I spoke to Samukelisiwe she told me that they have loaded 2GB day data and 2GB promotional data for me today which does not make sense to me another lady by the name of Mimi could not help me at all rather she made me feel stupid as if I don't know the reason of my call. May the MTN company give me clarity of what is going on with my new contract as they send me from one department to another and they is no one who can assist me yesterday some lady had to calculate my daily usage on data for the whole month and it was almost 4GB of data both for night and day then my question what happens to my other 4GB of data as per my contract. kindly assist me or cancel this contract I have been with MTN for more than 10 years and this is my worst experience I am getting from MTN