The Unison is ****ming us

Q living Apartments they're ****ming me, i want to move out even if I'm not owing them any cents, i sent them a text that I'm moving out Jan and i sent it on the 2nd of December and they said i can't move out End of this month i was suppose to sent them on the 1st of Jan, Remember I'm on month to month lease agreement. They said if i wanna move out i must pay them R5 800 and I don't know why coz the contract state that we need to notify them before 20 days