Wow, OP, that isn't very nice of you. That 'nice' person went out of their way to help you, yet you have blown them off in what could be considered a worse way than the 'bitch' person did to the rest of you.

Being nice to the person who helped you out is the least you can do. You can still be wary of them if you are not 100% sure of them, but kindness, especially after they helped you out, costs nothing.

You should feel bad. But you can still do the right thing.