Fitness membership

I called one of a fitness center here in our area a few hours ago and asked about their membership. I heard that this Just Fitness for You fitness center is cheaper than the other center around the area. I talked to a lady and I asked about the cost of the membership but she never told me she asked for my phone number and my name so that she could call me back. I gave her my cell number but she called me back on my house phone. I never answer because I wanted her to call me back on my cell phone. I wonder why she would not tell me the membership fees when I called. I want to exercise tomorrow but I can still walk in the park. In the park there is no membership and I can still do the exercise that I do in the gym.