Edgards - try to ***** money from old people

My Mom has an account with Edgards she is 84 years old and she only leaves the house when we go with her. According to Edgars she made a purchase at one of their stores in August and cannot tell us which store this purchase was made at. After numerous attempts requesting Edgards to inform us where the purchase was made they cannot tell us, how is this possible? I went to their Centurion branch and even then they refused to inform me where the purchase was made. If there is ***** on my mothers account why are they not trying to assist me to resolve this issue. I have requested a statement from Edgards but still they just sending me a front page to say what is outstanding. They are harassing my mother saying she must pay but she never made the purchase in August. It looks like edgards is making up the purchase just to get money out of her that's why they are refusing to assist with this matter.