I received a valid quote from this business on a a...

I received a valid quote from this business on a apartment. I followed through with the quote and a group of us gave Homestead at Reston/Panco Management a deposit and our information for a apartment. They gave us a lease to sign and we all signed the lease along with an application fee. They now are saying they made a mistake and they shouldn't have given us a lease for less than 6 months. They will not honor our 3 month lease. This surprise came after they have talked to us via email and phone several times (after we signed the lease) with no indication that they this was a "policy" of theirs. They will give us the application fee and the deposit back, so their isn't any major financial impact. The issue is with their business practices and waiting to tell us and not being willing to live up to the quote and the lease presented to us.