Double charge over a month ago - the Edgars run around

My daughter was double charged for a purchase made on the 11th of July. She has since then been given the run around from Edgars to the bank and back again. She handed in her bank statements and has been back to East Rand Mall three times now. Today she is told that the query was canceled as Head Office has not received the Bank Statements. What does a young person need to do to get their money back? Is this the way Edgars earns extra revenue? Interest on other peoples money?