Hello Seb,
Kindly refer to AniaC's post to contact Support, reset security code cases have to be handled outside of the F-Secure Community.http://community.f-secure.com/t5/Mobile/Forgot-lost-your-security-code-Read-this/td-p/7439
For alternative way to unlock your mobile, refer to the following post:http://community.f-secure.com/t5/Protection-Safe/f-secure-mobile-password/m-p/11397#M2688
Thanks.