You can try calling them thru their telephone number posted on their website. Or you can try messaging them on Facebook. If you still cannot send your email, I think it is better to call the main office, so the management is immediately notified of your intention to cancel.
What happened with me is that I emailed my cancellation request to customers***, but they still ask me to visit their extension office at a mall where I got the insurance. I thought when I go there, the matter would be resolved, but the agents insisted that I should not cancel and all, and they say things that it is not that easy to cancel and wala naman silang lapses so bakit ako magcacancel. But I know that within the free-look period, I have all the right to cancel and get a refund. Long story short, it got so ugly. I got mad until yung manager na kumausap sa akin, saying sige iprocess na nila. January 29 pa ito, but today lang ako naka-receive ng decision ng management approving my request. I am processing the documents for refund, pero nasa 2k din yung nabawas sa kabuuan ng pera na binigay ko.