im 18 and was a foster child, me and my real grandma had a falling out a good six months or so ago, and we have not spoken to each other since. until today while at my work (a fast food restaurant) i was given the phone by my manager i told someone wanted to speak to me. it was her and i have no idea how she got my work number without knowing where i worked, (she lives in another state) so i explained i was at work and cant talk, she told me i was going to talk to her that moment so i just hanged up, she continued to call and my manger would bring it back. this happened about three times before i asked the manger if we can just not answer to her anymore. she continued to call and this brought back memories from my past and i was shaken up by all this, so i asked to go home and was allowed this. only to find out once i got home that she had called my sister and foster parents claiming i had said all the things about them that were untrue, also that i was talking to my biological mother who tried to contact me that morning but i did not answer. she said she was going to keep calling and hoped i lost my job also that i was a manipulative little shit and so on. then to find out she posted on my facebook that i was in contact with my biological mother and that showed what kind of person i am, so i had to delete this from my timeline once i saw it. (sorry for the long story) is there anything i can do to stop this? im worried she will call my work and tell them untrue things about me that may get me in trouble or at the very least cause me a lot of discomfort around my coworkers.