having to lie to people

I am lieing ( is this the correct spelling) to people more than ever before now. In my junior years I had been admonished a lot for lieing and had got over the habit the hard way. Now, again I am having to take to the habit. When I say the truth, people just do not go away. They keep standing there and plead for what is not legally theirs. It is sad, but then I have to take the stance that I will look into the matter when I know very well, that I have already invested more time than is appropriate in the case. But then to enable me to have some time to work, this becomes necessary. I hate it; but cant make those around to understand too.