After you file

I have used Turbo Tax for many, many years.  I tried to e file my 2019 tax return after completing thru my TurboTax account and you emailed back that IRS wouldn't accept it via efile.  You did not have any explanation as to why and said I must mail my return.  I mailed July 9, 2020 and began calling IRS in September, 2020...checking 'where's my refund' as well as calling IRS.  Finally, sometime in October, I believe, IRS acknowledged receipt of the return.  but today, January 6th, the status via 'where's my return' still indicates 'processing'.  I have spoken with IRS reps numerous times and each time I am told they are behind and for me to continue checking website and/or call.  The IRS representatives can give me no reason why my return is still being processed.  They advised there seems to be no problem with entries, deductions, etc. and they don't know why it is being held up.  They did confirm it is in the Austin, TX office.  Last rep I spoke with on Nov. 23, 2020, advised that I should wait and call back around December 21st.  I have tried to call on several occasions and can't even get as far as a representative...message is to call back later or another day.  I am very frustrated.  First, because you couldn't give me a reason my 2019 tax return couldn't be e-filed when my tax information was checked and rechecked by Turbo Tax through-out the completion process and the final check before filing.   Second, because you are not helping me solve this problem.....