Virgin Active Sun Valley unacceptable behavior

Took my daughter to gym where she tried out a Grid class with me. Never in my wildest dreams had I expected a Virgin Active employee to laugh at my daughter and make fun at her expense with another employee & club member when she failed to be able pick up a heavy weight. It is extremely disheartening when a gym's employee calls you "lazy". Infuriated by this, I wrote to the club manager. I was told that this matter would be sorted out, but I never heard back. A while after this, the club manager approached me about the complaint, while laughing about the incident, literally instructed me to confront the employee about this?? I did exactly that as I could not believe this employee had not apologized to my daughter for her unacceptable behavior. Shortly after, I received a mail from the club manager, saying my behavior had been unacceptable. Gym should be a place for fit as well as unfit people to go and exercise comfortably, WITHOUT the fear of being ridiculed by staff members.