Bad customer service

Yesterday I went to Woolworths in adderley to return my sons shorts unfortunately I had misplaced the receipt, I was assisted by a cashier with a very bad attitude she first asked me where I bought the items and I told her my partner bought the staff, she then added that I have to take items she wont be able to issue me with a refund voucher, I then asked her if they have bigger sizes of the shorts I had because I wasn't sure it will fit my son she responded by saying " I don't know" she didn't even attempt to assist me.. I don't understand why Woolworths employees especially black cashiers treat black customers with so much disrespect !!! its a pity I never took that lady's name she's in the customer service department dark short with cornrows... I've been a loyal customer to woollies for so many years now im stuck with a shorts that doesn't fit my son.. can you please tell me what does your policy say with regards to returns with no receipt? stop treating black customers like we some *******