Ok, at this point your best course forward is to just print and mail the extension form and make any payment online at the IRS. You will have until April 20th to mail the form. You can include a copy of the rejection notification but the IRS will also have it in their system.
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/f4868.pdf">https://www.irs.gov/pub/irs-pdf/f4868.pdf</a>
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/payments">https://www.irs.gov/payments</a>
