Virgin Active makes it impossible to cancel membership

I am sorry to do this Virgin, as your service when I was attending your gyms was fantastic. But I simply do not know how to get through to you to cancel my membership. I have spent hours and hours (at my cost) trying to get through to the contact centre - it either hangs up, answers but stays silent, says the network is constrained or puts you through but keeps you on hold for at least an hour. When you do get through to someone they put you through to someone else - at which point the same thing happens - it hangs up, or you get put on hold for at least an hour. Eventually, when you do get someone from the right department to talk to you they say "the system is down". I've tried the website contact service - no answer. Ditto Facebook Messenger. And ditto commenting publicly on Facebook. So tell me - how can I get through to someone to cancel?