Is it permissible for a Muslim woman to respond to a Christian woman working in a closed sports facility with the same repulsive manner in which the Christian woman treated the Muslim woman?

A woman's non-adherence to hijab and her provocative manner do not necessarily mean she is Christian; she might be a heedless Muslim. It would have been better if you had taught her a lesson in ethics then, but now it is wise to forget the matter and direct your efforts towards what is beneficial. One must be cautious about going to sports halls where Sharia regulations are not observed, such as the presence of phones and the photographing of women.