Planet Fitness suddenly deducted R700 more per month without notice or reason

Planet Fitness suddenly changed my debit order from R237-25 for the past few years to R949-00 on 1 November, without consulting me whatsoever. I want to cancel immediately, but their customer service is absolutely pathetic. One cannot talk to anyone at the club, phoning customer service is virtually impossible and filing a request on the webpage do not get any response: It is as if they deliberately want to make it virtually impossible to contact them.