If this was a direct deposit to your bank account then what you received was probably interest from the IRS for a delayed tax refund.
Any refund from an amended tax return is Only sent to you by a mailed check.
Amended tax returns are taking 6 months or longer to be processed by the IRS. Go to this IRS website for the status of an amended tax return - https://www.irs.gov/filing/wheres-my-amended-return
