Misleading Bonus offers and therafter bill

Once again, I’m absolutely DISGUSTED with Vodacoms online sales / promotions department – they had offered misleading and incorrect information to me at an additional expense that I did not budget or agree to. Vodacom - Please can you retrieve and listen to a call that was made to me by Mandy on 11 February 2020 on about 09.44am, she offered me a bonus 5G data until the end of my contract period (which I hope it is still true).I had confirmed over and over again that what was being offered to me was at no additional cost, which the agent agreed to…however this is untrue as they have now billed a prorated amount for February and a full amount for March for the so called 5G bonus data. I need this resolved asap!!!!!