Lack of customer service

I bought a black friday subscription with Vodacom 3 years ago. It expired and no one from upgrades contacted me to upgrade my account and it lapsed.. I get a bill for R1160 (Initial Bill R281) i query it and they inform me you did not upgrade and this is the fee. I call into Vodacom and i get transferred to this person and that person until i get to After Sales and i speak to a lady call Keketso. She sells me the dream that the amount will be credited and she has seen that my account is about to be generated with a new invoice while we busy on the line she will send a cancellation for that so i dont pay it this is on the 01/12/2024 and then i will upgrade my line with a 5G line.

Fast forward 3 weeks, only now i get a credit of R760 on the 1st bill and R1420 on the 2nd invoice the one she was supposedly have cancelled once i did my upgrade.

She then send me a email illustrating that im now liable for the R1420 and there is nothing she can do i must speak to customer care

Over 1 hour on the call with customer care and the lady turns around and says sorry she cant help me either. I ask the question who can and she says no body.

I ask the question to her if someone from Vodacom called me at the right time for upgrade and i did the upgrade would i be liable for all these fees. She said no you would only be liable for the new premium..

I did nothing wrong, but do the lack of customer service i need to be liable for these fees. That is unacceptable!