IonCube depends on the servers OS whether 32 or 64 bit on windows or linux, etc... Please check that you've the right version for your server. Your host should be able to help you with this or set it up for you actually. Additionally if enabling with PHP.ini you must place PHP.ini in your Joomla root as well as root/administrator.
If you need further assistance please PM Joomla backend login credentials as well as FTP credentials. It maybe possible your host needs to provide you with a "default" PHP.ini before you can provide the necessary zend_extension change.