use strict;
use warnings;

print "Search for a name: ";
my $userinput = <>;
chomp $userinput;

my %data;
my $readfile = 'TextFile.txt';
open(my $fh, '<', $readfile) or die "Could not open file '$readfile'$!
+";
while (<$fh>) {
    chomp;
    my ($name, $date, $amount) = split /,/;
    $data{$date} = $_ if $name eq $userinput;
}

print "$data{$_}\n" for sort keys %data;

__END__

mike,2015-07-26,$-93.00
mike,2015-10-16,$69.00
mike,2015-11-08,$28.00
mike,2016-04-02,$95.00
[download]

• You could use Text::CSV, but this was trivial enough for split
• Store the data in a hash, with the date as a key and the whole line as the value. See also perldsc.