There is a possibility to recover these deleted files with Norton Ghost (i think that this program try to recover deleted files).
Try to contact with the admin of this server (if you can´t contact directly upload a txt file called "Admin_read_it" or something else in the root of the server) and explain to the admin inside this text file WHICH files you deleted.
Possibly if the admin had a backup of these files or a program like Norton Ghost he could restore the files... but pay more attention the next time