Why is my late-cancellation fee higher than the percentage suggests?

Because a fine is never smaller than $1 in your currency, even when the percentage works out to less.

Fines are a percentage of the game price, so on a cheap game the result can be a few cents, which a card can’t even process. The floor makes every fine payable.

The floor never pushes a fine above the price of the slot, so you never pay more than the game cost. A forgiven cancellation stays at zero.

You see the amount before you join and again before you leave, and both show the number that will actually be charged.