BIG PROBLEM HERE

I HOPE someone here can help me with this problem. I accidently set a permission on a folder that's on my server, but now I cant change the permission, I can not access or open the folder. "Could not change perms on Joomla: Permission denied:
How do I resolve this problem?
Please Help me ...

If you have a panel (cpanel for example) maybe you can fix your trouble, if no, ask your hosting to fix them.