The IRS is blaming “COVID-19 mail processing delays” related to processing paper tax returns due to closures made in an effort to slow COVID-19. The IRS has reported a backlog of 4.7 million paper filed tax returns. If your refund has still not arrive, you may want to reach out to the IRS National Taxpayer Advocate helpline at 877-777-4778 like the filers in this article.