DSTV lies about 3 months free Disney Plus

I have been a DSTV premium client for about 20 years and really frustrated with their lack of client service. I got a email confirmation from them saying they have given me three months of free Disney plus. Each time I log into my Disney plus, it still does not show the three months. I contacted Disney plus and they said because DSTV is a third party supplier, I need to contact them. I tried sorting this out via their call centre and social media pages, with no luck. I used the same phone number when I signed up and my phone number has not changed since 1999. I have deleted & re-installed the app, I tried it from my laptop and all avenues possible, but my three months free, as promised by DSTV, is nowhere to be seen. This is honestly very frustrating, especially the airtime used to try and speak to a call centre agent.