Sounds like you had some confusion over the 3rd EIP payment and answered incorrectly. There was no "2700 each" -- the 3rd EIP payment was $1400 per person. The IRS send you letter 6475 showing how much you received. And you can check your bank account for deposits of $1400 per person that were made sometime after mid-March. Also check your online IRS account to see how much the IRS says they sent to you. You say you received $2100 each--which suggests that you had one dependent and received a total of $4200 (3 x $1400). Is that what you received? Is that what the IRS shows they sent to you? What amount did you put on line 30 of your Form 1040?
LOTS of people have made mistakes this year with the recovery rebate credit by "forgetting" that they received the $1400 per person stimulus checks last year. They answered no to the questions for the recovery recovery rebate credit and put the $1400 per person on line 30 of their returns. But you cannot get it twice, so the IRS removes it when it is there by mistake.
Try checking your online account with the IRS
https://www.irs.gov/payments/your-online-account
Does the IRS show that you received a $1400 stimulus or EIP check in 2021? Did you receive it? When you were asked on your tax return did you say no? Was there $1400 on line 30 of your tax return?
If the IRS says you got $1400 last year but you did not receive it you can have it traced.
LOST THIRD STIMULUS CHECK
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-round-economic-impact-payment-top...
If you need to trace a payment that the IRS says has been issued to you, mail or fax a completed IRS Form 3911, Taxpayer Statement Regarding Refund.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
