Upgrade nightmare

Upgraded to a Apple iPhone 12 pro max 256GB at the end of September. At no stage in the easy conversation was I told there was no stock at all country wide. I have called every store in Johannesburg and nobody has stock and nobody at Cell C can tell me when stock will arrive. My old phone broke and I am using an ancient phone. I work on my phone. I am losing productivity daily as this old phone cannot support my work. This is unacceptable. I expect Cell C to come back to me with an urgent solution. Today. At the very least, I should be upgraded to a 13 pro max 256 at the same price as I was told by one of the store team that she had been told to offer this. Please call me Cell C, I demand resolution.