@arr=("c1,s1,d1","c2,s2,d2","c1,s1,d2","c1,s2,d3");

print "\nWith duplicates: \n". join("\n",@arr);
foreach $elem (@arr)
{
        $elem=~m/(\w+,\w+)(,\w+)/; #Input assumed sane
        $seen{$1}=$2;
}

#Now you have a hash with unique (client,status) combos
#Rebuild your array
@arr=();
print "\n";

#Rebuild you array, without duplicate entries
foreach $key (keys %seen)
{
	push(@arr,$key . $seen{$key});
}

#Note that order of elemens varies because of hash
print "\nWith duplicates removed: \n". join("\n",@arr);