Recovery Credit Error

It appears the IRS changed my return due to the 3rd stimulus check. I had mistakenly answered that we "didn't" get a 3rd check and was expecting a refund of $1311. Now on "Where's My Refund" it states that my balance due is $1489 (which I understand), but it says a letter was mailed over two weeks ago.

 

If I never get that letter how do I go about making this change so I can pay my balance due and have the proper taxes filed? Do I need to amend my return on TurboTax?

 

Thanks