Well, that was illegal. They have to give you at least a month notice, and it has to be via registered letter. And I'm not positive, but selling the house might not even be a legit reason to kick you out before the lease contract (that's what I heard from my agent).
in France it is a legit reason if the new owner bought the place to move in. Illegal if it bought the place with the purpose to rent it.
Same without purchase in fact. The owner can tell you to leave if it plans to move in.
I am however not sure if law is specific enough to avoid being exploited with loopholes like "owner move in legally for 1 month (while not actually living there and doing renovation), then start renting again to someone else"
