I asked for a raise when I was expected to fill in for the person above me while she was on maternity leave. The reason I asked is because the other employee who'd be filling my place did get a different contract to reflect the new duties, so I assumed it'd be the same for me. I got nothing and was basically told they'd just look into hiring someone from outside - probably a bluff, but they know I'm a single parent and can't really quit that easily.

I caved in, but also I've decided to move on and look for another job. They don't know the person I was replacing is also looking for another job and it's likely we'll both leave within the next few months.