Good post mp. On the surface it all sounds a bit childish, but I appreciate that we spend a lot of time at work, and feeling pushed out and unhappy is not conducive to a successful work life.
If they are just simply ignoring you, they sound very childish and petty. I would try to rise above it. They don't want to be your friend, sod them. They can only bother you if you let them. Can you get yourself some nice choccies, offer them around, phone a friend at lunchtime and make (or even pretend to make) some exicting plans.
Transactional Analysis is good for these kind of situations. I'm not an expert and I'm trying to find a decent link. Years ago, I was new in a job, and had to deal with someone (been there years) who was very short and upleasant to me. It was very, very hard to cope with.
We did a course at work involving TA and dealing with difficult people. Probably too long winded to explain the process here, but basically I realised I had to get out of the behaviour cycle.
= He criticised me over something - I felt stupid and apologised, "I didn't know, I won't do it again" etc (The relationship was Critical parent vs Adaptive child) My response to him enabled his behaviour IFYSWIM
So the course taught the simple lesson that we were both Adults, worthy of respect, and that communication should be based solely on that level.
The next time the guy criticised me, I didn't apologise/grovel etc. I just took a deep breath and said something like, Of course, I know you need that paperwork today, you'll have it by this afternoon. Smiled politely, and moved off.
The change was remarkable. I stopped worrying about him all the time, stopped apologising, and just responded to him with clear statements. In return, he stopped the criticism. I was totally surprised that it could be that simple. By the time he retired we got on really well.
Sorry - been waffling and you probably have no clue what I'm going on about....