am new to iphone and does not understand much. how do i retify my problem if apple deny service to iphone.

Have Apple refused to service your iPhone problem in store? If you book an appointment to your nearest Apple Store to see someone at the Genius Bar, i'd imagine they would be more than happy to help with your issue?

If not they better have a good reason for poor customer service.. On their own products..

Well, without knowing the problem we really cannot say. Keep in mind the warranty is one year on new devices and only valid in the country where the device was originally purchased. A warranty is not insurance. If the issue is a result of abuse, you're not going to get the issue fixed for free.

What is the problem you are having?