MTN DATA QUERY

I have signed a contract with MTN for data of 40GB (20GB Day & 20GB Night),last month I received data for 20GB ( 10GB Day & 10GB Night) and I have lodged the query( Query ref no:***) regarding the amount of data in received based on the interaction with the branch at Melrose Arch they lodged the query on my behalf and after 7 day, I went again to the branch the query was resolved based on the screen the showed me at the branch. This month I checked the data it is still the same data that I complained about, my sim card number *** and My full name is Madumetsa louise Mamaregane. Please help me to resolve this problem of Data