Wrong behaviour in php7

So, we had a working aplication on php5.6 and we updated to 7.0. Most of the app is still working properly but there is this one thing we cannot sort out.

When I navigate to '/ajax/sendContact' it returns a 404 error and shows the 404 error page but I've got a controller named AjaxController whit a sendContact. So i went to the dispacher and deactivated the not found handler. Now, instead of the 404 page it dumps the code in the controller and throws an exception. Anybody knows whats happening?

//
            var_dump($e);
            $contenido = ob_get_contents();
            ob_end_clean();
            $new_contacto->soap_exception = $contenido;

            if ($new_contacto->save() === false) {
                var_dump("error");
            } 
        }

        if ($new_contacto->save() === false) {
            var_dump("error");
        }

        echo $new_contacto->http_response_code;

    }

}

AjaxController handler class cannot be loaded

#0 [internal function]: Phalcon\Mvc\Dispatcher->_throwDispatchException('AjaxController ...', 2)
#1 [internal function]: Phalcon\Dispatcher->_dispatch()
#2 [internal function]: Phalcon\Dispatcher->dispatch()
#3 /var/www/html/webpromos_adri/public/index.php(28): Phalcon\Mvc\Application->handle()
#4 {main}