IRS Is Not Recognishing my Garnishment

IRS has garnished my paycheck for 3 years. Each year they start over for same year and same amount When I called their customer support line, the representative said they have no record of my previous garnishments. In other words they will not acknowledge previous two years of garnishments and completed two times now and are asking again. Have sent back their paperwork twice that said I was relieved of the debt and of course they wanted the originals. The debt is $ 740.00 each time and because of the little amount know one will take this up unless I pay much more than the value they just keep telling me to just pay it its cheaper!

 

What can I do next?