If you received a letter from the IRS you may contact then for questions by following the instructions below:

Call  800-829- 8374
Press 1 for English
Press 1 for letter you received
Press 5 for all others
Enter your social security number (if you wait long enough the system bypasses this option)
Press 4 for all others

If the system says they cannot help you now and to call later, hang up and call back again as many times as needed until they put the call in the queue.

Be patient, the IRS does not have enough infrastructure in place to attend to all the calls in a reasonable amount of time. You my have to try on several days in a row to be successful, but try not giving up.

Keep in mind that the IRS does not like to speak to anyone about individual tax declaration except the person or persons who are in the declaration. So your tax preparer will be limited to what he/she can do for you. Even if the the preparer has added him/her self in the declaration as a third party, the IRS will likely not speak to him/her without a power of attorney in their records allowing permission to that person to discuss the declaration with the IRS.