Sim cancellation horror

Before the month of February started I tried canceling my Sim. Their site was down. Under maintenance. When it got back to working the option to cancel sim was not working. I then followed up in their Facebook to ask that the sim gets canceled. After a good 7 days they managed on their side. My problem is. I’m no longer using the sim. But they say I must pay for this month. I’m writing this because I won’t be able to pay , firstly because it was them who we’re doing maintenance, secondly because we were not notified as customers that the site will be down and should we wish to cancel our services we should do that on the days the site was working. I feel like being liable for this debt is unfair for me, while it’s them who were maintaining their site and not communicating with their clients.