Poor service from Vodacom

On 10 Jan 2023 I upgraded my cell phone and signed a new contract for R308.98 at the Vodacom shop in Hatfield. However a week later Vodacom emailed me an invoice for R320.80. I queried it at the Vodacom shop in Hatfield. They lodged a complaint. After 9 days I called ***. The consultant told me the error was fixed and I would get a credit not with my next statement in Feb (no apologies offered). On 14 Feb I did get a credit note, but also an invoice for R446.36 instead of the contracted R308.98! I called again *** and told Adam of the problem. I had to hold on for 11 minutes, then he came back and asked me to hold on again as he has to speak to another dept. I refused to hold on any longer and asked him to call back later today once he has an answer. This of course did not happen. I am posting this on hellopeter, because this is from past experience the only way to get an answer from Vodacom.