You are entitled to a home that's "habitable". Determining whether your place is or isn't habitable is the key. Simply some mold growning on some walls wouldn't do it, I wouldn't think......
The problem is, I don't know how much of a fight you want to get into for two months. You're certainly going to wind up in court. You certainly might lose, and have to pay for a home you didn't live in.
If it was me, I'd just give my notice NOW and go when the lease is up.
PS> If you want to fight them, however, I'll tell you how. I hate landlords who rip their tenants off.