I got a letter from the IRS stating there was an error on my 2021 Form 1040 which affects my Recovery Rebate Credit. I now owe $8,000 more on my taxes??

I just got a letter in the mail today (ironically, it's future dated as May 2, 2022 but today is only April 30, 2022 lol)
And it says the same thing- and now I owe an additional $1400.

The 3rd stimulus for us should have been a max of $5600 but we only received $4200. So on my 1040, line 30, it shows a credit of the difference which was $1400.

Now they've taken that off and say I owe it. I do NOT believe I owe it. I would be really freaking out if it said I owed another $8k!!! 

SOOOO Frustrated with EVERYTHING about taxes since all this mess started with Stimulus and the Child credits etc. It's been a mess. 

@jennyebean 

your IRS letter should include a cutoff date before which time you can appeal the adjustment and not have to pay now.

(it's unlikely your appeal will be successful. But maybe you do have a case.)