No Unemployment Tax Relief

Filed my dependent daughter's 2020 federal taxes prior to the rules change with unemployment tax relief.  She owed about $1,200.  After the tax relief was passed I reran her return and it showed a refund due of $800.  Everything I read said not to file an amended return and that the IRS would recalculate those impacted.  Never received the refund and now received a letter from the IRS saying she never paid the $1200 and there are now interest and penalties due.  Should I file an amended return?  Who should I talk to to straighten this out?  Any guidance in appreciated.