Bad experience at Queenspark Herm****

I bought a dress at Queenspark Herm****. I paid cash and return the dress because it did not fit. The clerk at the shop could not refund me in cash, because the manager was on lunch and she did not have access to the safe. She gave me then a tillslip as proof of the return. I went back at a later stage and the clerk informed me that the previous clerk was no longer in employment and she was suppose to have given a gift card. The told me that the would sort it out with headoffice. After several enquiries nothing happened. After several months I am still waiting.