Hello engrshahrukh,
I am assuming you live in the UK and if so the law is very strict with regard to racial discrimination.
If this happened to you I feel you have every right and I would urge you to report this person for for racially discriminating against you, especially in front of staff and customers alike.
If this happened to me an apology would not have satisfied me.
Not being too sure of how the law stands with regard to discrimination, my advice is to first contact your local Citizens Advice Bureau (CAB). The CAB are extremely helpful and knowledgeable about this kind of thing. Also anything you say to them will be held in the strictest confidence. It is a completely free and unbiased service
You can also consult a solicitor. The first consultation in the UK is normally free. If you pursue a claim using a solicitor, it could be quite expensive unless you qualify for Legal Aid.
I recommend you see the CAB first.
If you go to the links below you should find out a lot more information about Racial Discrimination:
Welcome to the Commission for Racial Equality
Be comforted by the fact that not all we Brits or the rest of the world discriminate against people, no matter what their race, colour, creed, sexual orientation, or religion, or indeed age.
Good luck and I hope this has helped you.
Cy
(Poseidon)