I Hate the Internal Revenue Service

About 3 years ago, we got a notice in June that we had not paid our taxes for the previous year and were being assessed penalties/etc. We responded to the notice with a copy of the canceled check that they had received the first week of April. Then in October, we got another letter threatening liens/garnishment/etc. Luckily, wife's brother is a tax attorney that contacted the IRS on our behalf. He said they didn't understand why the letters ever went out, because the issue had been resolved BEFORE THEY SENT OUT THE FIRST LETTER!