my credit card got flaged by steam and now i cant buy anthing

I recently tried to buy Steam credit, and there was an error, and apparently my card got flagged or something, and I think it is from when I gifted a game and they sent me an email saying There was an error with a recent Steam purchase; the person I sent the gift to didn't redeem it, and I didn't charge back my card. And ever since then, I have been unable to buy anything. Do you guys have any fixes aside from getting a new card?