I am platinum with Total Rewards. I achieved it by having a Visa card and spending over $10,000 on it. However, my tier score is only 653. So my question is - how many more tier credits do I need to get to Diamond? Is it 15,000 minus 653 - or 14,347? Or is it the difference between Platinum level (5,000) and Diamond level (15,000) - or 10,000?