Maybe it's because you're a temp? Like they don't see the point in forming a working relationship with you because you will be gone after Christmas? Not that it excuses them from ignoring you of course, and it sounds unprofessional, workplace is not schoolyard we all have to try to get along - it saddens me when people are petty with co-workers.

Rude customers, well that's part and parcel of customer facing jobs I'm afraid. Most of us don't enjoy that aspect, all I can suggest is shrugging off the bad experiences and focussing on the good ones - that helps me feel more positive about my day.

Actually the really awful customers can be a source of amusing stories in the staff room where I work - it's good to share the load with others in the same boat and let off steam. Often the rudest most pettiest customers can be unintentionally comic I find. Unless it's plain abusive/threatening (a colleague of mine had her life threatened, nothing funny there - that's a matter for security), then keep calm, diffuse with apologies/validation and shrug it off then laugh about it later if you can or focus on what went right that day instead.

Good luck in your new job!