Cell C - Terrible Service!

On the 15 May 2024 I received an upgrade status call from Cell C. After finding out from the agent that I will only be paying +-R800 per month on my account, I was exstatic! 17 July 2024 I received an sms congratulating me on the upgrade. After reviewing my account status, the Cell C app notified me that the amount due on 31 July 2024 will be +-R1900. I cannot afford this massive amount! I have been trying to get hold of and "you will be called back" since the 17th July 2024 with no luck. It is now 29 July 2024 and STILL NO FEEDBACK AND NO SUPPORT. I think it would be better if I cancelled my contract.