The $2,800 that you received on March 17 was the third payment. You should enter $2,800 in TurboTax when it asks how much you received for the third payment. You received more than you qualify for, so you will not get any additional credit on your 2021 tax return, but you do not have to pay back the extra amount that you received.
The $1,200 that you received in January is the second stimulus payment. It does not affect your 2021 tax return, even though you received it in 2021. Do not enter the $1,200 anywhere in your 2021 tax return.
