Super, I will ask someone who is good with the saw Then I assume the floor doesn't need to be fixed? However, it does flex a little.
Thanks for all the very helpful responses!
It is a company, and they were supposed to be trained in carpentry, but I choose not to name them to avoid trouble..
Now, I think it would be best for everyone to name the company and write reviews on, for example, Google. If no one says anything, they'll just keep on going and ruin things for more people...