When a guardian is bias what can be done?

Before my mom got demntia, she and I shared some storage units toether for serveral years. We both agreed she would pay it. My mom had lived with me for over 7 years. She has other kids who destoryed her life 7 years ago and who she wanted no contact from. Now she has dementia and the kids who she didn't want around her and who have stolen from her in the past came back into the picture. We have been in and out of court. A guardian was appointed for my mom. She beleives my brother and sister and goes out of her way for them. The things in the storage units belongs to my mom, myself and my kids. There is nothing that belongs to the other kids. The guardian tells me my brother and sister said I dont own anything and it all belons to my mom. The guardian allows my brother and sister to go through the units. We have a court ordere stating the guardian, myself and sister are suppose to be there together. I have been by at least twice unanounced and found my sister, brother, ex husband, nieces at the storage going through my things with the guardian's permission and now I hardly have anything in the units. Thye have stolen almost everything from me.The guardian allowed my brother to rent a unit and put all he says is my mom's things in it and I am not allow me to see what they are claiming is my moms. Yhe guardian would not allow me into the units to et the proof to show her the things were mine and she would not allow me in to the unit for another case whre I had proof but she denied me access to get it andf now the proof is gone. Where are the rights of my mother's and I? Everyone is acting as if my mother is dead.