acl unwanted {
    "69.60.116.0"/24;
    "69.90.119.207";
}

sub vcl_recv {
    if (client.ip ~ unwanted) {
        error 410;
    }
...
}

error 403;

return(synth(403, "Access denied"));

acl unwanted {
    "69.60.116.0"/24;
    "69.90.119.207";
}

sub vcl_recv {
    if (client.ip ~ unwanted) {
        return(synth(403, "Access denied"));
    }
}