Should I have given more warning for stopping to babysit a misbehaved child?

I babysat this 4 year old boy for 3 days. He does not listen that well and the first day he also hit another child. I told the mom that he hit someone and she didnt' seem surpirsed and didn't say anything or follow through.In the morning, she is just 'good luck' and leaves. The next 4 days he hit one more time, swore once and lied. This is on top of his doing exactly what I ask him to stop doing and his not understanding what he is doing wrong. At four my daughter knew what she was doing, why she got punished, etc. He will whine, nag me asking over and over when I say no... he doesn't seem to understand what or why he gets in trouble. Finally today I had it... he was in time outs alot of the day. I told his mom that he has hit, sworn, and lied and that I can't have that aroudn the other children. She said she was surpised and asked what swear word he said. She seemed surpirsed which made me wonder if I should have given a warnign first, even though I didnt' want too, I just gave notice