Clera Windows + Doors

We had all of our windows replaced last year in October 2020. This included getting rid of the doors and windows that led to the backyard. The person in charge of the group promised to come back and put in/fix the capping on the outside as a favour. Now we're in December 2021, and it still hasn't been done, and they've never come back. Every promise we got about them coming has never followed through. Almost every call placed personally to their numbers were rarely answered. Even a "We're sorry, we're too busy" would suffice, but we got nothing.
On one of the windows we had installed, they totally forgot to do the caulking, causing major leaks. We had to do it ourselves this summer.
Yesterday, there was heavy rain, and it was leaking from one of the corners of our bedroom windows. We took pictures, and circled where it was coming from. We sent it to the 2 people that were in charge of installing those windows, and they replied by sending it to their services department, then no updates.
We called the head office telling them the situation with our windows, and they asked "are you sure the rain is coming from the window? You should do a water test"
At this point when it was happening, it was 10PM. Are we supposed to go up to the roof and pour some water to check? We were all watching the water leak from the window. We took pictures and circled where it was coming from in the photos. They said they don't take emergency calls, and their workers are all scheduled 4-5 weeks in advance.
In this case, what are we supposed to do every time there's heavy rain if there's no one to call to come look? Even when there wasn't an emergency, nobody that came to do the work would pick up. What are we supposed to do?
If we could give less than a 1 star review, we would.