I left my husband and at the time we were renting a house. He claims that he couldn't pay it so he subletted?

it out to a family. It didn't say anywhere in the lease the subletting was not allowed. However he has been having some trouble with the landlord since this happened and he told her that she needs to repair things as a landlord is required. Well today, I get a notice on my door stating that we (as I guess I was on the lease so I am also responsible) it says that its a noice of immediate termination because someone other than him is living there. Can they do this? If so what do we do about the subletters? What will happen in court? Is this a civil matter and can we state the subletting is not illegal in AZ. What can I do?