My question involves landlord-tenant law in the State of: California

For the past year and a half, I've been living in a house with a couple other people. Their names are on the lease, and they are sub-leasing out an unused bedroom to me. Three weeks ago (on the first of the month) my roommates gave me a 30-day notice to vacate. Then a few days later, they changed it to 60 days, presumably because they discovered that I have a right to more time, given that I've been here more than a year. But I ended up finding a place within 30 days anyway. Now they are saying that I am responsible for paying for next month's rent, because I didn't give adequate notice and they don't have time to find a new roommate. This doesn't seem right at all to me. Is a lessee still expected to give 30-day notice, even when they're being forced to vacate by the lessor?

Just to be clear, they are not claiming I did anything wrong. They just want a different roommate, and I donít want to stay where Iím not wanted.