TERRIBLE SERVICE FROM ADIDAS

I bought a product from Addidas Factory shop in Stoneride Shopping Centre. I returned it over 3 weeks ago with a request to exchange for a different colour (black). On checking the system the manager said they do have one in the stock room but that there was such a mess there that it would take a day or 2 to sort through it. ( Why is the stock room in a mess- this is the engine room of every retailer ???). I left my number but heard nothing from her. I tried calling but the line rings forever. I even went in a week ago and the manager said she had not looked in the stock room and would phone their Woodmead branch and call me back. Still waiting for a response from anyone. Shocking service indeed!!. Very disappointed. No £WIN AT THIS STORE