Help me out Mommy's!!!

How ironic that my last post (that I wrote just this morning) was offering advice and now I am on here blogging asking for advice! There has been an issue going on for awhile with my 7 year old daughter about her lying. I was also very suspicious that she was taking things. She would come home from school almost every day with a toy, book, etc that she said someone gave her. I told her after several days of this that she did not need to bring anything else home, she has enough stuff as it is. But, she continued to bring things home, not only from school but from places she visited. (Not talking about stores but family members homes). She had an excuse every time for each thing she would have.. "I got it out of the treat box at school", "Me and my friend traded" etc. I knew something was going on because why were there so many of her friends that would be generous enough to give her all of these things. So I sit her down, told her stealing is wrong and she needed to return these things the next day. Days pass and I would go to clean her room and find said property hidden in her room, not returned like I had asked. I have tried everything I know to explain to her that stealing & lying are wrong. An example: One day I caught her with a bottle of lotion she had taken out of my bathroom, when I made her return it, it upset her, and she said "but you never use it, why can't I have it?" I explained to her that me not using wasn't the point, she should not take stuff without asking regardless. I would have given her the bottle of lotion had she asked but the point of her just taking it upset me.

I got a phone call today from the guidance counselor at school telling me they are having a problem with her. Her teacher is on maternity leave right now so she has a fill in teacher. Apparently she has been leaving the classroom without asking permission or saying she needs to use the rest room and she has been wandering the hallways instead. Every time she is approached by a teacher she lies and says she had permission. Then today in the computer lab the teacher saw her take a peace sign stamper that she did not have permission to take. When the teacher asked her about it, she lied again. So, the teacher asked her to take it out of her pocket and Catie acted like it wasn't a big deal because she had been caught. I try to teach my kids difference between what is right and wrong, but apparently it's not getting through to them. Please give me suggestions and advice. Also, how in the world do I punish her for this? I am desperate! I do not want my child labeled as a liar nor a thief. I am strongly against both and do not want my child to think it is okay!