Vitality Active Rewards very shoddy

I have earned a diamond reward with Vitality and am unable to redeem it. After a 27 minute conversation with an agent telling me that I can't use it and will lose it if i don't earn an additional 150 points. On the App and the website it shows that a diamond is equal to 100 points. Vitality is saying that you can only redeem the Diamond(100 points) if you have earned an additional 150 points or another diamond. In other words you need 150 points or another diamond to use the diamond you earned or you lose it. What is the actual point of earning a diamond then. They sent me the Rewards guide via email but I have viewed that already on the website. They also emailed the rewards Active Rewards rules but the problem is I can't find it on their website. Not having my query resolved I requested to speak to a manager to resolve it but conveniently there is no manager who can take my call. I need this resolved today. I refuse to accept something I was not told about.