You have turned the wrong bit ,screw that back on hold the metal bars of the shade and turn the plastic ring below it, they often jam up, new holder may be best as said above
Turn it 3 times to the left, then 2 times to the right, then, finally, 4 times to the left. That should free it up. It's a safe bet that that will solve your issue..
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local