A 24.99% APR isn't 24.99% a year. Compounded daily, it works out closer to 28.4% — the card charges you interest on yesterday's interest.
Your card says 24.99% APR. Carry a $5,000 balance for a year with no payments and you don't owe $6,250 — you owe about $6,419. The extra $169 isn't a fee or a mistake. It's what happens when interest is calculated every single day on a balance that already includes yesterday's interest.
— Educational, not financial advice.