struggling to get money back when returning the merchandise

my daughter bought a dress and after two days she was not happy with the purchase she decided to return the dress, upon arriving at the shop she was told they don't have cash she must come back on Saturday. She did what she was told, on Saturday same story no cash available she must go back they can phone her when cash is available, my daughter she is in boarding school she can not leave the school premises when truworths summoned her to come get the money, already turndown twice, is inconvenience for her to get permission to go and still come back without was she was hoping to get, am very disappointed because i even try to intervene and speak to the shop assistant who did confirm that is unfortune that they are unable to assist her .