Incorrect Contract

I took out a contract on the 29th of February 2020. I selected the 1GB FreeMe at R349, the consultant who assisted me selected 2GB FreeMe at R399. I went back on the 2nd of March to query this and a case was lodged. My issue is that this has not been rectified and i have now received an invoice of R891. How? My case number is ***3. I was assisted by Gabi Dube at Telkom Maponya Mall. Telkom Maponya Mall does not answer their phone. The call centre puts me on hold the entire day. I need this sorted out immediately please, as the debit date is imminent.