Ok ... the credit was worth $1400 for you and $1400 for your spouse thus $2800. The program told you that you were eligible for the credit then asked you how much you got in advance in the third stimulus credit so if you entered zero the program gave you the full credit you were due. So when the IRS checked their records they believe you already got the advance so they removed the credit from your return and either reduced your refund or increased your balance due.
NOW ... if you have checked your records and you really did NOT get the advance stimulus payment then all you can do is have a trace put on the missing money...
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.
Updated IRS FAQ about recovery rebate credit
https://www.irs.gov/pub/taxpros/fs-2022-27.pdf
