work.....

So I answer phones and do data entry, there are three of us who answer all the calls and send them to who they need to go to. I have always been the receiver of people venting their complaints, for a while I was planning on being a therapist. So at work I hear a lot of stuff about one person in particular so I had been taking notes and when her performance began to affect me I went to my boss who didn't want to listen, so I went to the HR manager who listened and then my boss arranged a meeting for those involved. The person of interest got very defensive when the issue was mentioned and lashed out at me. I am not surprised but, you would think now that the issue was put on the table she would be aware of the problem and fix it the next day..... I was wrong. This issue is still happening and my boss either doesn't believe us or just doesn't want to hear it.... I am sure the saga will continue.