Asus — warranty denied

Address: Kamrup Metropolitan, Assam

ASUS zenfone 5 mobile has been given for maintenance in guwahati city service center and they told me to pay around 1500 rupee while it is in warranty. they told me the reason is damaged due to liquid, which i don't know how this happen because it never sink in water or used during rain or some other related. i need solution from the company to wave the payment. [protected] Hailu G.