Did you report that you did not receive the 3rd stimulus payment and the IRS removed that amount from your tax return? If so, the IRS has records which show that the 3rd stimulus payment was sent to you.
The Recovery Rebate Credit would have been entered on your Form 1040 Line 30.
You will need to wait for the IRS to send you a letter which will have the changes the IRS made to the return which changed the refund. If you disagree with the IRS there will be a procedure in the letter to dispute the IRS changes.
