Poor service at Woolworths

I wanted to exchange a shirt bought for me by my niece. The customer service was poor after waiting for about half an hour for someone to help. There were consultants talking behind the counter and folding clothes while there where atleast 10 people standing in the queue. As I reached the counter a unfriendly face looked at me as I greeted her. As my neice bought the shirt I only had the card purchase slip. I briefly explained the situation to the lady and was told that in the future I must bring the correct slips. The shirt was exchanged eventually. When she was finished helping me, I politely said thank you, expecting it back, but no response. I feel this is unprofessional and should be addressed.