You have a real issue with permissions on this server. Most of the files are owned by
fotosrus (10020) / psacln (2524)
I noticed that a bunch of your folders are set to 777 which is a huge security nightmare. Folders should be 755 in Joomla and files should be 644. The reason you set the permissions to 777 was that you were probably throwing Joomla errors as these directories not being writable. You can't keep them at 777. You need to chmod the files to be owned by apache. The reason I know this is because when I installed ninjaxplorer to look at your files, it was owned by apache after installation. You are on a VPS or other dedicated hosting plan, I assume.
The reason your install did not work, is because the Vituemart directory under administrator/components was set to 755, which was not writable because its ownership is not apache.
If you have suphp available on your VPS for server, then you can have the files owned in this manner with no problem, but suphp needs to be set up properly.
You need to get the file ownership issues worked out. Contact your hosting company if you need help. You need to get your folders back to 755 before someone hacks your site.
After that is taken care of, uninstall then re-install the Target Coupon component and try it again.
Good luck!