Do I have any legal rights in regards to something I signed but no longer want?

I went to an astrologer and agreed to have a service performed on me but now I no longer want the person's services. I have already paid money to the astrologer and the astrologer told me to write on the paper that i paid her a certain amount of money on a certain date and that I owe her a certain amount. (I only put my first name and her first name) That was the only thing I wrote on a blank piece of paper in her notebook. Can the person take me to court for the rest of the money for writing that or not since it wasn't on business stationery or my last name wasn't on it or what date I owed the balance?