Voda**** just automatically changes my tariff without authorization from me

After receiving my Bill for the month of April, I noticed that the usual payment was about R20 more than the last upgrade in June 2018 When I upgraded from a uChoose Flexi 150 to a uChoose Flexi 165. Upon closer inspection of my latest Bill I noticed that you have Automatically (Without my Consent) upgraded my Line from uChoose Flexi 165 to uChoose Flexi 175. I did not consent to this. After calling customer care, the agent said that her history shows that I have always had a Flexi 175, now this is not true, I have detailed accounts in pdf format that have been emailed to me since the upgrade and they all state Flexi 165. The agent said she would start an investigation and that i must send my history of accounts to her personal email address (Wonder why her personal Email?) which I did, Its been about 24 hours and I have no case number nor reference number for the investigation. VODACOM, PLEASE NOTE THAT come the 26th of april (Debit Order Date) and you take off the new amount, I will cancel your debit order and pay you the usual amount via EFT. Please wake up and wipe the **** from your eyes. I want a full apology from you and you better fix YOUR mess before 26th! I can provide you with the same statements that I provided Miss Mapaseka Zwane last night on her email.