Freeze it if you want it stopped but kept — a frozen card declines everything and you can unfreeze it whenever you like, but the card issuer still charges its decline fee, from the card, on every refused attempt — so if a merchant keeps retrying, close the card. Close it if you are finished with it: closing is permanent, it frees a card slot, and it returns the remaining balance to your wallet in full with no fee. Closing is currently the only way to get money off a card, so if what you want is the balance back rather than the card stopped, close it rather than freezing it.