If its really as bad as you think you should either face up to them or ignore them. I'm really good at ignoring people & giving dirty looks when I have to

Do you have to deal with them every day or is it just that you are all sitting in the same office space??
If that doesn't work then ask them in earshot of the boss why they are treating you this way, because bullying amounts to threatening behaviour - remember they are only doing it because you are letting them

This may all sound rather harsh but you're just making yourself unhappy & stressed by letting it go on.

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