My guess is that you have a reluctant landlord. Failure to pay rent is typically provides the landlord with the easiest and fastest claim to evict a tenant. It certainly shouldn't take a year to do. You may check the court records for your county to see if the landlord has started the process and it has, check to see where it is now. At least some CA counties have their court records available for search online. 

If the landlord hasn't even started then consider either moving out or filing a lawsuit against the landlord for breach of the covenant of quiet enjoyment. The term is an old one and doesn't specifically relate to noise but a number of states have included noise that the land can control as included within the right to quiet enjoyment. See a CA attorney for help if you want to sue, or least go the pro se legal resources office that I understand each county in CA has. The lawsuit might prompt your landlord to finally take action and get these people out of the building. 

Also, call the cops when the noise is really loud late at night/early morning. A few visits by the cops might result in some kind of resolution.