Facebook Personal Issue

i have made a group in face book the group privacy is completely ON and no one can see until i send them invitation via email.....

... i sent invitation to the person A but he/she didnt join that group ..... so now my personal group has grown and i have so many members.. but still that person A is opening my wall via that email link and watching it.. but i wanna get rid frm him/her......\\\\

plz help

You can block a user from accessing your account. Can't you?

I think you gonna have to contact FB administration on this one but before that go to ur profile and select all the options to "friends only" also check the detailed list of ur friend if this person has not accepted ur invite, it will showing a "status or request pending" and see if u can find some option to cancel the invite (which is likely :( )