How do I deal with a mom with dementia who won't accept help and wants to take money out of the bank?

I just was able to convince the nursing staff, nursing director, and geriatrician that my mother could come home that I'd take care of her. They feel she should be in a nursing home, but agreed to let me work with her. I have her going during the week to a day center for several hours to give me some relief. She is being cooperative, but seems at times to think that there is nothing wrong with her but old age. She has been diagnosed with advanced dementia, I don't think that medical staff have discussed this with her, but it is a fact and I have had to tell her this, she just blinks at me and says it is not true. She was telling me tonight that she had to go get money, Since I have to take full care of her, I made an appointment for her to get a haircut, something she had refused to do, she was okay with this but she was insisting that she had to pay for her haircut, well when she remembered that she was going for one. I told her that we would get her whatever she needed, whenever she wanted it or whatever she wanted, that I would help her do it. I told her calmly and kindly that she knows that right now she is not the best at handling money, she agreed, then forgot and started it all over again. The neighbors are starting again with their is nothing wrong with her, I am going to take the elder care social workers offer up to go and talk to them.