Title 49 USC Section 44709(a) is the law that we are talking about here.
I would suggest that you ask the FSDO if you can place your Flight Instructor Certificate on "Temporary Deposit" at the FSDO for up to 30 Days. This may buy you some time. Ultimately you will need to submit to the 44709 Re-Exam or possibly face Suspension of your CFI Cert Pending Compliance with 44709. Google FAA Order 8900.1, Volume 5, Chapter 7, Section 1 for complete details.