उस त्रेअसुरी Department

I got another letter today from the Department of the Treasury.Seems that I am getting six hundred dollars. Money that will be spent on my house.My letter went on to say that I should recieve payment around June 6. Today is June 2. My question is: Why did they even bother to send me a letter????? Why couldn't they have just sent the check??? Sometimes our government does things that I don't readily understand..