In my opinion the contract is (in french "nul"). A contrat is correct and legal when the parties are ok 1) for the price 2) the thing.
In you case the appartment provide by the company is not the appartment you signed for.

I think that the company is now in a bad situation.

If you accept the new appartment (the other) it's ok.
But you can cancel the contract.

If the other appartement is not absolutely similar or in a worse situation (to much sunny, to much noisy, not at the second but at the third floor, and so on) ask for a reduction.

Regards

Alexandre