Okay ladies I need some advice about this girl that will not stop texting/calling me?

Ok ladies I need some advice, so this random girl on plentyoffish started messaging me she seemed normal at first than she started coming off way strong like saying that I was her "bf". At first I thought she was kidding than I started noticing that something was way off about her. Than she told me that she is missing her thumb and middle finger & than she started crying saying people tease her. She will no stop txting/calling me. I really feel sorry for her & all but she is really starting to creep me out! I really do NOT want to offend her but its getting to the point that I almost need to say something so she will stop. How can I get her to STOP txting/calling with out hurting her feelings?