Got charged R500 after upgrading. Agent was unhelp

I upgraded my account just a few weeks ago, then when I receive my invoice I see a charge for an additional data bundle of R500. When doing the upgrade I specifically asked the agent involved if there were additional charges, and she said no there were not. <br> <br> When contacting the call centre, the agent \Noniko Maluleks"seems helpful and asks me to forward the invoice through to her and their systems dont have the invoice that they have just sent me??? Very strange.... <br> <br> however I ask for the email address and she says C-H-A... she pauses and then I confirm the letters she just said and then she says A-N-G-I.... She repeats it exactly the same way again : C-H-A... pause A-N-G-I "