What is the best way to get a hold of an IRS representative? I have an error code R0000-902-01

it saids this return was rejected by the IRS because the tax return for the taxpayer Indentification number was already filed and accepted by the IRS.  I double check his information and its all correct. shows I need to call 1800-829-1040 but i am having a hard time taking to an IRS representative.