HELP

i downloaded this app just for fun and to see who has been looking on my page. although the app is free, it does not give you any information unless you start a trial which is free for 7 days but then charges you $50 monthly!!!! i did not mean to click okay, i thought it would just take me out of it, but now it says my trial has started but i dont know how to cancel it!! if anyone could please help so i do not get charged $50!

Licoriceebony about Social Spy PRO – reports and analytics for your Accounts, v1.0