Samsung - warranty not covered on display on warranty period

I bought a Samsung galaxy s** ultra mobile phone on **/**/**** from Reliance digital Balasore.In the date **/**/**** i noticed a white strip line on my mobile phone display.Immediately i visited samsung authorised service center located in Azimabad,Balasore.At first they attended the mobile phone and saied that the display will be replaced by covering under warranty given by the company. They said they will handover the mobile phone to me after *to* days due to lack of spare part.Today they call me and said the mobile can not be repair under warranty given by the company.I called the customer service officer and he told me that the mobile phone has external damage,but there is not a single scratch on my phone.The service center staff told me to pay ***** ruppess to change my display.