If you entered incorrect banking information for your refund, you can change it if your return is rejected. If it is accepted, however, it is too late to change it. The bank will reject the refund and send it back to the IRS. Then the IRS will issue a paper check and mail it to the address you put on your tax return.
Here is what the IRS says about entering incorrect banking information
What phone number can I call to the IRS to actually speak to someone to get an answer to where is my refund?
Edited.
[Oops! I didn't notice you have another thread. So my answer was redundant.]
Here's how to reach a live agent at that IRS number. Hours 7 AM - 7 PM local time Mon-Fri
Listen to each menu before making the selection.
First choose your language. Press 1 for English.
Then do not choose the first choice re: "Refund", or it will send you to an automated phone line.
Instead, press 2 for "personal income tax".
Then press 1 for "form, tax history, or payment".
Then press 3 "for all other questions."
Then press 2 "for all other questions." It should then transfer you to an agent, but there is likely to be a long wait.
I usually use a speakerphone so I can work on something else while waiting.