Vodacom Took my V-up Prize Away

I am a 15 year subscriber to Vodacom. I have mine, my wife's and my son's contract through Vodacom. Recently I entered their V-up daily draw on their Vodapay app, and was delighted to win a 12 month subscription to Prime Video... for FREE. To say I was delighted was an understatement. I was over the moon. Then, not even 3 months later, they took it away. No explanation! I phoned their call centre and was politely told it's an 'Indian company' that does this and wasn't a Vodacom issue and that it probably won't be resolved. That's a problem for me as it was Vodacom that awarded me the win, it's Vodacom that took it away, it's Vodacom that I subscribe to and it's Vodacom that has a V-up competition... not an 'Indian company'! I then sent an email to their CEO via various links, abd got a lady from their SRM office who said they would sort it out. It's now almost 4 weeks later, and NO ONE has contacted me regarding the issue. I have, in the interim, sent other emails asking for ANYONE to help... and nothing, no response. How can anyone give you something, then take it away? It appears Vodacom can.