I think you're being taken advantage of. Is it your house? Technically I mean. I know you're paying rent, but your mother owns it, right?
You can give them a warning before you evict them, or have your mother evict them. You can get police involved if need-be. They are stealing from you and breaking set rules. You need to have this enforced. It may seem like you think you're being mean, but they are te ones being down right terrible and they need to be aware of this.