Once your return has been accepted (or mailed), it's too late to 
change your bank account for direct deposit.
If you haven't filed yet, you can still change your bank account info for 
direct deposit. 
If the info you provided is for a closed or invalid account, the 
government will mail you a refund check.
If the info you entered is someone else's account, banks won't deposit 
tax refunds into accounts where names don't match up.  The best way for you to 
track your federal refund is to call the IRS at 1-800-829-1040.