Vitality Drive Diamond Status will be damn near impossible to reach. The maximum points you can get per month is 1650 and to get diamond status you have to maintain an average of 1600+ points. Pretty much no room for error. You will also have to pay for the Advanced Eye Gym course and a Discovery Insure Driving Course.
Yes it looks like they don’t want anyone to be on Diamond status. You loose points if you have been with them for less than 3 years. After 1 year you only get 25 out of 200 and also loos points if you drive more than 500 km a month both impossible targets not even considering drive points