Don't keep ****** alive

Seems to be a bit ****** when it comes to serving customers. I am white and I went to have a document printed. She was busy helping a black lady and said she would assist me shortly. No problem, she was still helping the lady when a black man came in and said he sent an email and wished to have it printed. Still no problem!! After helping the lady she started helping the gentleman and when I asked whether my document is being printed she reckons me that the gentleman was there before me and that is a problem!!!. I still waited a minute or so and then walked out. I was about 20m away when another lady said I must come back and she would assist me. Now why did she not offer assistance while I was in the shop??? I politely told her I would go elsewhere and left