dropped

Hi so we've had this door fitted about 5 years ago I'm sure there a 10 year warranty with it. We've had nothing but problems the door is constantly dropping we've had them out twice to fix that last one was about 3 months ago, the guy mentioned they might have to change the hinges. We've also...

Talking to a general builder doing some dry lining in my place, says he mostly does bathrooms these days, because "everything has dropped and needs reworking". Is tilebackers/bath sat on the same horiz CLS/batten a good solution?

Please see attached pictures. This window seems to have dropped a little and there is a gap at top which lets in a lot of road noise & draught. The window itself opens & closes perfectly. Windows are in place about 13 years. Any thoughts on what I need to adjust to seal it up. Many thanks.