Welcome to our community and thanks for posting. Sorry to hear that you would like to cancel our F-Secure security.
As our valued member @newapollo has already given you some great advice already, have you managed to speak to a member of the team to cancel your subscription? You do get the first 3 months for free, and it is the £30 for the year. For more information check the link here.
If you still need further assistance with this request, please come back to us.