From what I'm reading you amended your tax return once you had the corrected 1099, if that is the case you should be able to get a copy of this amended return from the IRS.
However if you are using Turbo Tax, the information about the amended return should be there once you transfer last year's information to this year. If it doesn't, enter the amount you did receive and TurboTax should take care of the rest. To make sure, click Forms at the top of the screen, look at the list of all the forms, Recovery Rebate Credit should be one of them, if not go to the Federal Review and it should take you right to the questions asking how much stimulus you received. If you didn't get what you should have then the program should make the corrections for you.
I hope this was of some help
