I transferred to a zero balance card, unfortunately I did not know that it took 3 weeks, and thought I didn’t do the transaction correctly so I did it again. Then both transactions hit. Even though I called right away and the 2nd balance transfer was returned within 24 hours, I still ate the 2nd transfer fee. Nothing they could do. So word of advice, if you open a discover acct for the zero interest, it takes 2-3 weeks, but once opened, i t only takes 24 hrs to process