Looking for a comedy film from the 70' or the 80's, i hope i didn't made it up in my mind

hello everyone,
its going to be a tough one. i hope you will help me find it . i’m going to be as much detailed as i can hopefully it will help the search. i hope i didn’t dream or made up that film although i have a very vivid memory of that day i watched it. and especially the end scence , the whole film felt like a crazy comedy with a huge potential to be a cult film, and i remember that i didn’t laughed a lot but i was like “what the hell is going on here. i never saw such a film before”. as for the film, the film is a British or Australian comedy film from around the 70’s or the 80’s .also the actor that plays the main character i remember that he is the script writer of the film. both the actor and the director of the film they not have long filmography, around 3-4 films. also it doesn’t have a film poster on imdb or a trailer clip of it. it was broadcast on our cable tv service on the MGM channel but i remember that MGM didn’t produce this film because the famous lion trade mark at the beginning of every film of MGM did not appear on that one.

the premise of the film as i remember:
a young well know comedian or actor needed to go to somewhere else,
and to meet with someone or waiting for a call for a roll or something.

scenes i remember from the film:
opening scene: starts from a shot of the blue sky and clouds, the name of the film appears the camera tilt down and you see the character walk in a place that seems like a part of harbor and heading to the town that near that harbor.

during the film he meets with people in this town the neighbors he have in that building he lives there interrupt him and he gets phone calls or making phone calls to reach someone regarding his expected roll. and every now and then the apartment starts showing different parts falling apart in the kitchen or other places of the apartment.

the end scene: at the end the apartment starts to all fall apart and breaks down and get flooded with water the phone ringing but it far away from the character that trying to get a hold of al the mess around him you can see the phone inter to the frame floating on the water. and the climax of the film that some parts of the walls falls apart and somehow push the character outside the window to the streets hanging of some parts of the furniture that also pushed outside the window.

Based on the details you provided, the movie you are describing may be “The Plumber” (1979), a Australian black comedy directed by Peter Weir. The film stars Judy Morris and Ivar Kants, who is also the co-writer and main actor you mentioned. The movie follows a young couple who experience strange occurrences in their apartment when they allow a plumber into their home to fix a leak. The plumber seems to be intentionally sabotaging their apartment, causing it to fall apart and leading to a chaotic and surreal final scene where the apartment is completely destroyed.

Although it was an Australian film, it may have been broadcast on the MGM channel as part of a distribution deal. The lack of a trailer or poster on IMDb could be due to the fact that the film is relatively obscure and not widely known.

After checking this film on youtube , this is not the film. Thank you for taking the time to look it up and put your search result here.
For others that still looking and maybe i was not completly clear about the discreption of the plot. The actor that playes the main charecther is in that film playes a charrcther of like a well known comedy actor or comidian that goes to some town for some sort of a job offer as much as i recall. And the apartment he lives is falling apart during his time there. Also the film is not made by a well known director that also have a very few film in his filmograjpy and the film dosent have a poster or a trailer on imdb.