Completely misleading upgrade offer

I became eligible for an upgrade around October this year, and apart from being bombarded with emails and SMSs from Vodacom, I received a call from a third party about an airtime offer that I was told would in no way affect my ability to obtain a new device when my contract term officially ends in Feb 2023. Guess what? I'm now told by Vodacom that I'm not eligible for a new device! I'd like the call to be retrieved and listened to as I asked multiple times about being able to add a new device in February and was assured multiple times that this would be the case - completely misleading! The airtime package was effective from 1 December, it came with 20GB once off. I'm completely happy with the upgrade being rescinded and paying the costs of the additional airtime and data received thus far. I was also told that I would receive an email confirmation of the said upgrade after the call but this did not materialise. I only received a generic SMS a few days before the upgrade took effect (on 29 November). I'm not satisfied that third parties are able to offer Vodacom services and are completely misleading when obtaining approval. I'll be taking this matter further if there's no satisfactory resolution. I tried to contact the call centre after my initial discussion about this, but could not stay on hold forever (I called two departments). I've been a loyal customer since I bought my first cellphone!