The IRS sent me a note proposing changes to my 2018 taxes, and asking me to pay them a few thousand dollars.
I accepted their changes and paid them.
I've now learned that their changes were wrong and I don't owe them. Is it too late to fix? I think I should file an amended tax return (the way I think it should be now, probably with an account's help) and they'll give my money back? Is that right?