Drain Rescue Plumbers

There was this strange noise came up on and off during day and night. It sounded like vibration from the pipes and so we checked yellow pages and called a near-by plumber - Drain Rescue. A male plumber came in blue uniform looked pretty professional. He ran up and down, turning on and off every faucet. He said there was air trapped inside the pipes. I paid him cash ($68.25) for the work he did in less than an hour. I asked what happen if the noise came back. He said "you could call me back". I did because the noise came on the very next day. This time, a female plumber came in. I told her what took place yesterday and she said we needed to intall a T-pipe at the main knob and it would cost $398 plus labour. I said no, I thought the other guy didn't have the problem fixed. She said angrily, "I came for nothing. Bye" and walked right out! How unprofessional could it be!