Vodacom deal not honoured.

I app**** for a Black Friday Special on Vodacom for Vumatel Fibre on Monday the 28th November. The deal was on a month to month basis at R499 per month with the 1st 4 months free. I took a photo of the deal from a store , as well as a screenshot of the deal on the Vumatel site. I was contacted by a gentleman from Vodacom who took me through the processes and credit vetting criteria and later called me back to say the line was approved. The router and back up LTE solution were delivered the next day Tuesday 29th Nov and the installation of the fibre line from outside the house to inside took place the following day Wednesday the 30th Nov. I subsequently cancelled my line with my previous service provider and hoped that all this quick turnaround on the delivery of the routers etc were a good sign of things to come. I was utterly surprised when my 1st deduction went off for the amount of R1597.99 on the 31st of Jan 2023 and I have been invoiced for R799 for the end of Feb 2023. Not only have I not got the 4 months discount I have been charged R300 extra for Dec , Jan and Feb. I pray that I don't receive generic pre-typed responses and would like to hear from a human being.