VODACOM UPGRADE

I was due for an upgrade in August 2020 which I didn't do as they was no attractive offers available. In Nov/ Dec they sent me an SMS saying that if I upgrade I would receive an AMAZON PRIME VIDEO subscription for 6 months. I upgraded and received my new device and new data but no Voucher. Since December I have made many calls and had online chats with Vodacom but to to avail. No one could help, call would get cut off , online chat would get disconnected etc. I was put from Customer Care to the Upgrades back to the Helpdesk but cannot resolve this issue. The Staff of Vodacom don't even know of this offer that was sent to me. and I am very disappointed with Vodacom in general. I received a reference number about a week ago and then an sms saying that the case is closed(?) without me even knowing about it. If VODACOM want us us to upgrade they must not lure us with false offers as I regret doing my upgrade.