This sounds like you have a rouge php.ini file somewhere and it is loading the wrong one.
There are actually 2 php.ini files in WAMPServer as in most PHP/Apache installations.
One is called \wamp\bin\php\{phpversion}\php.ini
and this is only used by the PHP CLI
The other is called \wamp\bin\php\{phpversion}\phpForApache.ini
and is used when you are running PHP through Apache.
If you use the wampmanager menus you will edit the one used by Apache/PHP i.e.
wampmanager => PHP -> php.ini
However if you have actually edited the correct php.ini then it is likely you have a rouge version of php.ini somewhere on your system.
Run the phpinfo()
link again from the wampmanager homepage and check this parameter which is shown on the first section of the output.
Loaded Configuration File
It should be pointing to \wamp\bin\php\php5.5.12\phpForApache.ini
in your case.
If its pointing somewhere else then you probably tried to install PHP and Apache manually before finding WAMPServer and that has left a php.ini file somewhere where Apache is finding it.
Here is the PHP Manual page that defines the search path order used by Apache when looking for a php.ini
file. This may help you find and remove any rouge versions of php.ini