How to cancel HipChat

Except as otherwise specified in your Order, all subscriptions will automatically renew for periods equal to your initial Subscription Term (and you will be charged at the then-current rates) unless you cancel your subscription through your account at my.atlassian.com. If you cancel, your subscription will terminate at the end of then-current billing cycle, but you will not be entitled to any credits or refunds for amounts accrued or paid prior to such termination. Log in to my.atlassian.com to cancel

Or, you can submit an email web form to start the cancellation process: https://www.atlassian.com/company/contact/general-inquiries