Jira server Integration plugin uninstall

Recently i have configured jira server integration plugin in rocket chat. So i purchased the plugin with $15 through credit card last year (2021 aug month). After testing, i have unsubscribe the plugin (January 2022) . But still billing is going on with $15 on everymonth. How can i get rid of this. Could you please help to me in this, it would be great.