Zone Fitness Campus Square

In November 2021 i went to register at Zone fitness. I've been paying since December and haven't gone once. My old work closed down and I use to get paid on the 25th. My new job pays me on the 31st but my money only reflex's on the 1st going into the 2nd. I sent an email asking the gym to change the debit order date and they refuse to do that because they said I signed a contract stating I'll pay on the last day of the month.. So they debit on the 1st it bounces then they debit again on the 7th and adds bank charges for the 1st debit order bouncing. HOW DOES THIS MAKE ANY SENSE! I will be contacting the national consumer commission.