No working aircon

The aircon at Planet Fitness Brackenfell has not been working properly/at all for months. We have started an e-mail group where we constantly email management, but they have stopped replying and are ignoring our concerns. We mainly use the studio and the other night it was 31 degrees in the studio, my heart rate went up to 202bpm whilst gyming. I can literally prove this on my fitness watch. It's becoming a health risk as some of the members also have asthma and are struggling to breathe as there's no ventilation. But we need to keep paying. I don't want to move gyms because it's down my street, but seriously this is not on!