If you purchased Audit Defense for the year in question (2013?), call TaxResources, Inc. at 877-829-9695 as soon as possible. Do not contact the IRS. TaxResources will contact them for you.
If you did not purchase Audit Defense, what you should do is pay the $2,687 by the deadline in the letter. If you cannot pay, call the phone number in the letter right away and see if you can set up a payment plan. If you cannot pay or set up a payment plan, or you think that you don't owe the amount they are asking for, you should get professional help right away. You must respond, one way or another, by the deadline in the letter.
You have ignored two previous notices. The CP503 is the final notice before the IRS starts taking steps to seize your assets or garnishee your wages.
