If your provider can't fix it (they should be able to, but sometimes providers are incompetent), and if you have shell access to your account (no need for root access), you can install the module yourself:

Assuming your home directory is /home/jaysoon, create a directory like /home/jaysoon/perl-modules, and invoke the CPAN shell like this from the command line:

perl -e'use lib "/home/jaysoon/perl-modules"; use CPAN; shell'
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Then, answer a couple of questions and at the prompt, say

    cpan> install Image::Thumbnail
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Once the module has been installed, quit the shell and use

    use lib '/home/jaysoon/perl-modules';
    use Image::Thumbnail;
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in your Perl scripts to pull it in. This way, you can manage your modules without dealing with the provider every time.