If the IRS encounters any problem sending the direct deposit, they change it to a check sent by mail. They don't spend any time trying to figure out why the direct deposit didn't work, or trying to make it work. Also, they will not send more than three direct deposit refunds to the same bank account. Any additional refunds are sent by mail.
It's possible that the direct deposit never got to your bank. Ask the bank what the correct routing number is for direct deposits, and make sure you entered it correctly. Also double-check the account number that you entered.
