Deleting files and Reversing the Process ( need help )

So,i deleted few files like 15 days ago or so
havent been doing anything else since then
now i figured out that i had important notepad file there or rather to say .txt file
i succesfuly recovered it but i recovered it as $ID9CXSL
that was the new name of the file and i dont understand why it was renamed
but fine that wasnt the problem
the problem was that content in the file
was deleted as well
the only thing that was inside was
few random letters and then it showed the particion where the file was before it was deleted
can some1 help me how to recover content from such files ?

Hm,bad luck.If you have written on your HDD something,then it is difficult to recover files.
Try Testdisk oder ask Kroll Ontrack for assistent if the file was very valuable for yor.

hmm as far as ive seen
TestDisk works only if i delete my whole disk,reformat of what ever
means i would need to delete over 500 gb extra for just a file which is less then 300 kb,
i doubt its worth doing all that
true that file is very important important,cos it has a password email and rest of informations of mine for an account of a game....
but if there is no other way to recover it,than i dont know,but still dont understand how can i see the file,it shows the file,and when i open it,it shows different content,why is that ? kinda sucks -_-

Ask kroll Ontrak for assistence.I Think This is better than try by yourself.