I think that a table-driven approach might make the logic of what you're doing more evident:

my @cases = (
  { 
    osname => 'INTIM', 
    total => {
      duration => \$ototalintimdur, counter => \$ototalintimcdr.
    },
    freecall => {
      duration => \$ointimfreedur,  counter => \$ointimfreecdr.
    },
    voicemail => {
      duration => \$ointimvoicedur, counter => \$ointimvoicecdr.
    },
  },
  { 
    osname => 'TOUCH', 
    total => {
      duration => \$ototaltouchdur, counter => \$ototaltouchcdr.
    },
    freecall => {
      duration => \$otouchfreedur,  counter => \$ototaltouchcdr.
    },
    voicemail => {
      duration => \$otouchvoicedur, counter => \$otouchvoicecdr.
    },
  },
)

if ( defined $osname{$num1} ) {
  foreach my $case ( @cases ) { 
    next unless $osname{$num1} =~ /$case->{osname}/;
    my $calltype = ( defined $freecall{$bnum}  ) ? 'freecall'  :
           ( defined $voicemail{$bnum} ) ? 'voicemail' : 
                            undef;
    my @counter_sets = map $case->{$_}, grep $_, 'total', $calltype;
    foreach my $counters ( @counter_sets ) {
      ${ $counters->{duration} } += $dur;
      ${ $counters->{counter}  } ++;
    }
    last;
  }
}
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