Unfair management practice? District manager is aware but does nothing?

In the past year we have had 3 employee's quit because of my manager's attitude and the way she handle's things. She gets paid salary and is supposed to be at work at 6am and leave at 3pm, she shows up every morning a little bit after 7:30am and leave either early or on time. All the employee's come up to me (i'm the istant manager) and complain about here coming in late and how she always sits at her desk doing nothing (putting make-up on, balancing her check book, talking to other manager's on the phone about un-related work things). People bust their es around there and she always gives them **** on how it wasn't done right, when she gets paid over two thouand dollars a month to come in an hour and a half late, and then sit there all day and not do anything. Recently i had reported an obvious theft to her and when i had came in the next day she was at the home office, left me no note about if he was fired (he was working 3rd shift weds-sun and it was Tuesday) since my manager was at the home office at a manager meeting i decided to call my zone manager (that has been aware of everything that has been happening at the store including her coming in late and not doing anything) and asked her what was going on with that and she had no idea about it. She asked me to send her an email of all the times that theft happend and i did what she told me and at the end i said that it was obviously not brought to her attention and my manager was very offended by that because she thought that i was trying to get her in trouble. The next day my manager and i had talked, she closed the office door and was basically screaming at me the whole time and had the nerve to ask me if i needed to leave because she didn't like my attitude, when i never had an attitude, she was screaming and i was trying to defend myself because she took the email completly the wrong way. She told me that it was too blurry for her to see him not pay the full amount when he clearly didn't. I defended that and said yes it is clear and she then asked if im telling her how she should do her job, after that i just sat back and listened to what she said because if i was to say how i felt about anything she would have fired me. Question is, this has been going on for more than a year and was watching camera on me when i had to work a double and had everytime that i walked outside and was on my cell phone the whole night and is going to dock me 4 hours (the total hours that i was in and out of store and on my phone) when she is on salary (im hourly) and even though she comes in an hour and a half late every single day for over a year and does nothing but sit at the desk, makes cashiers do her work. If my district manager is aware and is doing nothing is there a hotline that i can call or should i just go to the owners of the company because he is unaware of all of this and if he knew my manager would have been fired. I'm in jepordy of losing my job all because i reported a theft and the main 3rd shifter was on vacation and she didn't want to deal with all them 3rds that the theif had that week. so she is watching camera on me to get anything she can get so that she can fire me, i havent stole, i have been on time everyday, i finish all of her unfinished work, cover ALL call offs, but she doesnt respect that.. what do you think about this and what should i do?