This isn't very pretty, but it demonstrates the use of unpack to solve your problem:

#!/usr/bin/perl
use strict;
use warnings;

my $template = 'x2A4A8A4A3x2A6A5x2A5A5x2A4';
my ($bus,$service,$day,$time,$from,$departure,$to,$arrival,$avail);
while (<DATA>) {
        next if m/^\+/;
        next unless /^|/;
        ($bus,$service,$day,$time,$from,$departure,$to,$arrival,$avail
+) = unpack($template,$_);
        next unless $bus =~ /[A-Z]\d/;
        print "Bus $bus of the $service service, arrives at $to at $ar
+rival, from $from, leaving at $departure on $day. ($avail)\n";
}

__DATA__

---TEXT BEFORE---


+---------------+
| Bus Timetable |
+---------------+----+------------+-----------+------+
| BUS SERVICE DAY tm | FROM  DEPT | TO    ARR | 24/7 |
+--------------------+------------+-----------+------+
| C4  metro   mon 15 | twn   0900 | Apt  1011 | yes  |
| C6  intl    mon 45 | LDN   1000 | XTR  1426 | no   |
| B2  susx    mon 20 | cly   1034 | btn  1118 | no   |
| A0  xxxxx   xxx xx | xxx   xxxx | xxx  xxxx | xxx  |
+--------------------+------------+-----------+------+


---TEXT AFTER---
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Output

Bus C4 of the metro service, arrives at Apt at 1011, from twn, leaving
+ at 0900 on mon. (yes)
Bus C6 of the intl service, arrives at XTR at 1426, from LDN, leaving 
+at 1000 on mon. (no)
Bus B2 of the susx service, arrives at btn at 1118, from cly, leaving 
+at 1034 on mon. (no)
Bus A0 of the xxxxx service, arrives at xxx at xxxx, from xxx, leaving
+ at xxxx on xxx. (xxx)
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