Disrespectful staff and unfair treatment

I am a member of viva gym Sunningdale for almost 4 months now, I haven’t had one problem with them or the staff till now. Today they forbid me from entering the gym despite the fact that my payments is always on time and complete. The staff did not want to let me in because i did not take a gym towel with. They stated that it is a must but in my contract that i signed there is nothing stating that i have to take a towel with every day. They treated me unfairly and the staff laughed in my face when i walked out. I am not happy at all and thinking about moving to another gym.