Help a sister out.

As mentioned in my last post, I started a new job. It kind of fell into my lap immediately, though when I applied (and interviewed) I thought it was for the following fall. After a whirlwind, I started this past Monday.

It's easily going to be the most difficult group of students to win over I've ever encountered.

A little background:
The first teacher in this class (4 sections of upper-level reading intervention and 1 section of READ 180) suffered from medical problems. She had excessive absences and in the midst of her absences the students never saw her for more than two weeks in a row. The number of subs is currently incalcuable. The school finally was able to post the position and put a long-call sub in until they could fill the position. The long-call sub was wonderful, but had no teaching experience and no reading license.

What they've been doing:
Curricularly: They are not even through two units in their Read 180 curriculum, the students haven't finished more than 3 segments (at most) on the software and their idea of independent reading is sitting around chatting with friends.

Socially: Swearing is more than tolerated. The students are allowed to call teachers "f---- b---"es and other things with no disciplinary action on behalf of the administration. Phones - students have been allowed (in this class only) to not only have their phones out, but to listen to music, text, and just about whatever they want, even while the teacher is instructing or giving directions. Computers - students have been allowed to listen to youtube music during READ 180 time (which make no sense, since the software has audio), and were frequently given 15-20 minutes (in a 51 minute class) for free time on the computers.

What I need:

Help! How do I effectively intervene in this instruction so that these students are getting the most out of their class, and begin to recognize me as an authority in the classroom and begin to trust me. I'm afraid to take away all their music/privileges/etc because a: they'll just walk out of class with no consequences from administration and b: they will riot. I have no doubts a full-scale rebellion would ensue.

So, experienced teachers, help a girl out. I have 8 weeks to turn these kids into readers.