Want to quit new job, few questions I need answering?

Hi

I basically started a new job this week, I already have a night part time job so this new one is a part time daytime job.

However the job was advertised as Monday Tuesday Wednesday mornings, which is why I applied. They have however given me Wednesday morning. But also Thursday and Friday afternoon, which means I'm now working 6 days and 5 nights a week.

I'm not happy with this at all, I've asked to move one of those to morning but they said they will see.

I'm not interested in this job now and my heart isn't in it.

1. Can I just quit / not show up? I didn't sign a contract just an employee bank details for my wages. It is contracted 16 hours a week.

2. I don't want to go in, I might just send an email saying the job isn't for me or whatever, then just not go.

I could do with the extra money but not at the cost of my happiness and spare time.