I have no OO techniques to suggest, just write clearer code.

Don't repeat yourself so much. This :-

        if ($intermediate_array[12] eq "GSM" && $intermediate_array[9]
+ eq "MSubmit")
        {
            $intermediate_MO_cnt++;
        }
        if ($intermediate_array[12] eq "GSM" && $intermediate_array[9]
+ eq "MSubmit" && $intermediate_array[7] eq "MsgAccepted")
        {
            $total_MO_success++;
        }
[download]

could be written as :-

    if ($intermediate_array[12] eq "GSM" && $intermediate_array[9] eq 
+"MSubmit") {

        $intermediate_MO_cnt++;
        if ( $intermediate_array[7] eq "MsgAccepted") {
            $total_MO_success++;
        }
    }
[download]

It's clearer and easier to see what your intent was, and there are fewer places for bugs to hide.

Variable names like $del_user1_error , $del_user2_error, .. $del_userN_error are always a sign that you should have used any array and you're writing too much code. So instead you could do something like this :-

    my @del_user_error_count;

    for my $i (0..4) {
        if ($cdr_post_array[11] eq $del_user_errors[$i]) {
            $del_user_error_count[$i]++;
            last;
        }
    }
[download]