Frustrated by with Gym

Today I went down to the Gym only to be told that I could not go in because my membership had expired. As normal I leave my wallet in the office as it is safer there. So I came all the way up to get my credit card and went all the way back. The lady at the counter proceeded to fill in my details then asked for my staff card. As a contract employee I do not get a staff card which I explained to her, but she was relentless in her decision. I even told her I was on the staff directory and she could look it up on the internet, but she was still unmoved saying that it was possible that I did not work there anymore. Strange thing is when I joined, I was not required to show proof that I was a staff member, so I suppose it depend on who is behind the counter on the day. The only way I can join now is to get a letter of employment, which I have now got. Hopefully she will be there again tomorrow so that I can shove it in her face.