doesn't the notice provide a means to object to the change other than trying to call? i would send back the notice with an explanation, and support if available, as to why the IRS is wrong. keep a copy of what you send and keep trying to call. sadly the IRS is receiving more calls than it has phones and agents to answer. another possibility is to try to contact a local IRS office to set up an in-person conference. again multiple attempts may be required.
