Do not try to retaliate. This will only backfire on you.
Since you have already tried to address the problem with her personally, you need to move up the food chain. Send an email to your mutual manager, detailing the situation just as you have described it here and requesting a meeting with both the manager and the woman in the seat next to you to address the issue. If the manager can't or won't help with the situation, take it up with the Human Resources department. What she is doing has a name: "creating a hostile workplace." You might want to use that phrase in the email, along the lines of:
"I'm sure you will agree that a hostile workplace is counterproductive to the goals of our company. Linda's continued harassment is creating an untenable situation that is rapidly moving in that direction. While each individual occurrence may seem minor, the accumulation of these small matters is creating a very unpleasant work environment that is interfering with the smooth operation of this department. Since repeated polite requests have had no effect, I hope that you will be willing to help the two of us come to a mutually agreeable solution to this issue."
Most companies have specific policies to deal with these issues.
Be prepared to produce documentation of the situation: keep a journal with dates, names and times; if possible, use your phone to take photos of the workplace as it appears when you arrive (this will likely be unnerving enough for her -- when she asks why you're doing it, just smile sweetly and say, "Oh, it's something for HR, that's all.")
26 Feb 2012, 6:03 pm
