I received a IRS letter saying they need a 1040x form

 1-800-829-1040  hours 7 AM - 7 PM local time Monday-Friday

To get a human agent do this:

After first choosing your language, then do NOT choose Option 1 (refund info).  Choose option 2 for "personal income tax" instead.

Then press 1 for "form, tax history, or payment".   

Then press 3 "for all other questions."

Then press 2 "for all other questions." 

- When it asks you to enter your SSN or EIN to access your account information, don’t enter anything.  

- After it asks twice, you will get another menu.

Then press 2 for personal or individual tax questions.

It should then transfer you to an agent.

Or you can contact your local IRS office.  See this IRS website for local IRS offices - http://www.irs.gov/uac/Contact-Your-Local-IRS-Office-1