Sony India — Sony Xperia Z Ultra replacement

Address:

248001

I have purchased Sony Xperia Z Ultra in the month of February 2015.. after few days it broke.. i visit to a Sony care and they replaced and Handover the phone on 18th Aug 2015..after 3-4 days i faced lots of problem with the phone.. volume tab is not working, on and off switch is not working.. screen touch is not working smoothly... and now my phone is switched off i am not able to restart my phone.and my phone is 100% water resistant and Sony Care is saying we cant replace the wet visit so many times to Sony Care they told me that its a company policy that we cant replace. i want some suggestion that what should i do?