How do i deal with a teengirl who is mean and disrespectful to me?

I had a problem with this 16 year old girl starting back in october.She lives at this apartment complex,where I live and we have this business center,where the residents can use the computer,with a time limit.At least three occasions,Iwas waiting for my turn to use the computer,and she would not get off.When I asked her to,she would not acknowlege me. To make a long story short,she was rude,disrespectful,and mean many times.The manager posted a rule,that no one under 18 can use the computer,unless there with a parent or guardian. Three times I caught her by herself on the computer. When I told her she has to get off she ignored me The manager had to tell her many times to get off.She doesn't like me for standing up to her,for two months she called me names and taunted me.We had a meeting with her and mother at the managers office,but it didn't go very well.She never sat a the table,her mother more or less stood up for her daughter.I felt like this girl got away with it.

if her mother isnt going to play ball the only option left is the manager. Ask him to further enforce the rule. Be wery however that too much trouble with this and they will treat you like children and take the computer away...also id start saving for my own computer..

Wow. Well the first thing is I do think that rule of 18 years+ is silly but whatever. First of treat her like an adult in your post it sounds like your treating her like a child. Talk to her first then go to the parent. Second of all get in her world. If she's making fun of you reminder that you can't do that in the real world without consequences. Finally tell her to grow up.