I filed 5500 EZ Delinquent Filer Penalty Relief Program along with $1,500 check, solo 401k. IRS cashed the check but later sent me a letter asking me to pay. I replied that I already paid, that was in March 2021 with me sending proof of the cashed check.
Now I got a CP 283, demanding I pay $300,000 within 30 days! I called the IRS number and the rep told me to fax documents, responding to the CP 283.
1. Should I contact the tax payer advocate?
2. What happens at end of October when the CP 283 is due in 30 days?
Any help is greatly appreciated as I am in a state of panic. Let me know if this is the best place to post or another sub-forum.