I also received the same letter about 4 weeks after I filed my return. I called the number in the letter, expecting to stay on the line for at least 30 min but everything was resolved within 10 min.
She asked me a few questions (ssn, amount to be refunded, name, address, filing status, etc...), just basic questions to ensure you are who you say you are to ensure the return is not filed fraudulently.
The lady said I should expect my return in 2 to 4 weeks and
I don't need to send in any documentations, just sign and fax her the
letter.
