I paid 2020 fed taxes. I got notice to pay penalty & inter. of 30.08. I amended after efiling (no change to tax amt) Do I ignore, can't get a live person?

[EVUser]

IRS phone ctr constantly says Due to High Volume, please call back later due to COVID19.  Their system confirmed they got my tax pymt on 4/26/21.
The notice gives IRS, Fresno, CA 93888 address.  
Do I send letter with ACH #'s (proof from bank for 2020 pymt) to Fresno address, that will take 30 days or more for them to get to?  I can't fill out 911 form for Taxpayer Assistance unless it's been more than 30 days and I haven't heard from IRS.  Please help!

[Mike9241]

this may be irrelevant but if there was no change in your taxes why did you file an amended return?  it's obvious the IRS knows about the payment and therefore the notice saying you owe penalties and interest is most likely because it changed something on the return.  does the notice give an explanation or show what was changed?