Doing something against the policy

On the 27 October I went to Woolworths Somerset to make an exchange of 2 dresses,that my sister has purchased in another region a lady called Olivia who was helping me she said I can't make the exchange coz it's a high price as for the Woolworths policy they have failed me as a client, a lady called Akhona came to explain that they had to keep my items for a 7-14 working days for auditing purposes,on day 10 they called to say the manager said I should bring in the till slip what went wrong to Woolworths and the service or is it because I'm black, I don't even remember them showing me the manager ,I just asked a guy I saw where can I find store manager he said regarding what ? I explained my story nothing concrete from Woolworths yet