Very poor service

For someone that had there account with Vodacom for over 20 years, (What bad service). It all started on the 28th April when I phoned the call centre to find out why am I been billed R2100.00 and my account does not come out more then R650.00 a month. When I phone in I was told that my data usage was R1500.00 and I wanted to know why cause I get regular SMS's from Vodacom telling me how much data I got. After speaking to 5 supervisors, 2 data tech agents and 1, team leader I have still not got any explanation why the high data usage and till today only had one agent phone me back and that was to set a data limit on my contract. From an account of R2100.00 then to R1221.00 and finally R727.00 with still not explanation I eventually paid the amount and till now still waiting for my phone to be activated(2 days later).