Hi, I moved into my basement appartment in the middle of…

Hi,
I moved into my basement appartment in the middle of December. The middle of January my landlord mentioned that they were looking at a new house. The next day, I came home from work and they had moved everything out upstairs. Right away construction started 24/7. I would call and ask them if they could let us get some sleep. The response was okay we'll tell them to work on the upper psrt of the house so that it wasn't right above us and the loud music and yelling to be stopped. It would get quiet for literally 10 mins and it would start all over again.
Having contacted you and getting some advice, I told them that having checked with the landlord and tenant board that they should not be doing construction after 6pm or the weekend, but we were okay with it as long as they finished by 10pm. I didn't hear back from them but the next day they knocked on the inside door which has no lock on our side it has a klock on their side so they can walk in anytime. Anyhow they knocked on the door and said a real estate agent would be down in 10 minutes.
They came down looked around and talked quietly amongst themselves and left. We haven't heard anything since.
We don't know if the house is on the market? My problem is this, we are paying $1200 a month. Paid first and last and they have cashed the February cheque. We have a written, signed agreement that they are to give 24 hiurs notice in writing if they want to enter the apparment. They have never done this we have 5 to 10 minutes although mostly no notice.
My son, 19 suffers from severe social anxiety. This has been really unsettling for him. Can I ask them to give us 2 weeks privacy without people coming down or them coming through. We would never have moved in here if we knew that they were considering selling. It's been a nightmare, I have had to miss a few days of work which I don't get paid for because of the noise all night. Can we ask for 2 weeks peace. I don't mean that they stop working upstairs as long as it's not after 10pm.

What should we do?

Sincerely
Geraldine