Some have suggested the Fireball Whisky helps a lot. If you have reached out to Practitioner Hotline, there is not much else to do.

If the client is upset enough, have them contact The Taxpayer Advocate https://www.irs.gov/advocate/the-taxpayer-advocate-service-is-your-voice-at-the-irs

I don't understand...why did you have to mail the 2021 return. Each year, in the eyes of the IRS, is independent. You should be able to e-file future returns regardless of whether or not the prior return was filed at all.

I filed the 2020 in March of 2022, then i filed the 2021 which the IRS rejected as a duplicate.  They said I had to paper file it.  If the IRS didn't reject it then Intuit did.

You filed the 2020 tax return on 2021 forms.

no i used the correct forms  I filed the 2020 taxes on 2021 forms in 2022.  The taxpayer was late.    They have received the 2020 refund, but they rejected the 2021 form filed on 2021 forms as a duplicate and said i had to paper file it. 

"I filed the 2020 taxes on 2021 forms in 2022"

You have to file the 2020 taxes on 2020 forms, even if you're filing in 2022.

no i miss spoke.  I filed the 2020 on the 2020 forms in 2022.  I tried to file the 2021 on 2021 forms in 2022 a week after filing the 2020 return.  the IRS or it could of been intuit rejected the 2021 return and stated i had to file it.