Hi, I've had a newly installed bifold 5 panel doors fitted on a new extension. I noticed a gap at the top, where I can see daylight, feel draft and hear noise. The window fitters came and packed inside the frame. It was fine for a while. However I now see a gap not all the way to top but about a 20cm gap. My doors are south facing. In the sun the door expands, closing the gap. In the evening the gap reappears and it gets difficult or tight to push the lever all the way up in to locking position. The window fitters came back and readjusted the locking jambs but still not solved the problem. Any idea what would be the solution. The window technician packed the frame last November 2023, returned in December 2023 saying that they needed to extend or add a new trim to close the gap, that technician left the company, so they sent another one last week. He adjusted the door lock jamb..Its becoming increasingly frustrating chasing the window company. What are my legal options? Should I go to FENSA. The company have given me the certificate covering the bifold door.