Terrible customer service - Call centre agents

I have recently upgraded my contract through Vodacom's call centre. Spoke to an agent that assisted me with the upgrade. Upgraded to the iPhone 12 Pro Max. I am aware that the phone does not come with a charge in the box. But, at the time of my upgrade, Vodacom had a promotion that a free 20W USB C charger will come with the phone. I saw this promotion on Vodacom's website. While speaking to the agent, he confirmed -multiple times- that I will be getting a free charger with my phone. I received the phone via courier. There was no charger in the package. I called the call centre. Agent that I spoke informed me that the agent that assisted me with my upgrade will call me back. No one called me back. I called again over the next few days. I was told many different stories. My query was escalated. I was told that a manager will call be regarding this issue. Today, 2 February 2021, no manager has called me with regards to a solution. I was promised a charger by an agent and each time I have called, I am given more and more excuses. Buying a charger is not a problem. It's the principal behind it. Vodacom and their agents should keep to their word that is given to customers.