Management backed out of rental agreement

My husband and I and the leasing office of an apartment complex signed a new lease last week. We were due to move in Dec 8th. This week we have been informed that we can no longer move in as the current tenants have changed their minds and decided to extend. They gave the required 30 days notice of their intent to move out but not of their intent to extend. What legal rights do we have against management? Is there any legal documentation we can show them that states our rights to move in on the date stated on our signed lease? We would appreciate a quick response. Thanks.

Management is in a pickle. They already promised you the place with a signed contract. The old tenants refuse to leave. This is why smart LLs don't sign a new lease before the prior tenants vacate. (We sign only holding agreements.) You can attempt to hold them to the lease. But it will take much longer than a week to get those old tenants out. If they refuse to leave, management would have to evict them to empty your unit. Insist that management provide you with different accommodations. Surely they have another unit available? Try that. If not, how you already given notice at your current place and could that be extended? If not, management is responsible for something for your inconvenience.