If your refund has been deposited in someone else's bank account, it's too late to change the bank information that you entered on your tax return. You should contact the bank, explain the error, and ask the bank if they will help you recover the money. If the bank won't help, you will have to consult a lawyer.
The IRS and the bank followed your instructions and deposited your refund in the account that you designated on your tax return. They are not at fault, and they are not obligated to correct your error.
See the following page on the IRS web site, particularly the third bullet under Scenario and the fourth (last) bullet under Solution.
What should I do if I entered an incorrect routing or account number for direct deposit of my refund...
