Changing goal posts to hold you back on certain paying out levels?

I am confused with the targets set on Vitality to reach a higher level. Between December and January the total to stay on my bronz level changed significantly. Again end of February and March... I did need about 4500 Vitality points and suddenly I needs 7500 Vitality points. All people who want to exercise, you van only get 300 points per day and as soon as what you reach 30 000 points, you can't earn more?

Does Vitality manage the payouts and change the goal posts as what they like. OR Does I MISS SOMETHING?