Overdue Refund and Calls avoided

I rerurned a dress on the 3rd September 2015, was told that I will be refunded within 7-10days, I have since not received my refund. I called on the 18th September since I decided to wait for 7-10 working days. I spoke to Elizabeth who took the details and promised she will come back to me after she contacted their Head Office. She did not. I called again, she had no formal response saying that she is still waiting for head office. I threatened to consult Hello Peter, only then she started reponding and communicating. The form I completed for my bank details needs the branch, not branch number. my refund was help because i gave them my branch name not number, so she says. I expect that store like theirs should have called me as a constumer to enquire and not wait for me to call them. Today the 22nd Sep, I still have not received my refund. I have been calling the store, she said she will check the progress and come back to me. She has not done so. I left several messages, Spoke to Ann, and she is still avoiding my calls. What kind of iresponsible manager or supervisor can ignore a client like that? I am disgusted by the behaviour of Elizabeth and Bride and Co. I want my refund pls.