A question about income tax?

If we have to pay income tax like the government and most ppl on yahoo answers say. Then how come when I have called up the IRS. I have received shady answers and lies. The first time I called up the IRS. I asked him if there was any law stating that income tax was a law. He answered me with shady questions and was very evasive. Just like a politician. Then another time. I asked a IRS agent to look up the Definition of the word income directly from the internal revenue code. She said that she wasn't allowed to do it, she could only refer to the Manuel's and if I wanted that kind of information. I would have to consult a tax expert. Then I asked her if the other 8 IRS agents were all wrong in providing me information from the internal revenue code. So obviously this IRS agent was bluntly lieing. So if we have to pay income tax, why does the IRS have to lie about the question then?