Amtrust Mobile Solutions - Declined insurance claim without a valid reason

On **th of Feb ****, I made an insurance claim for my mobile which was damaged accidentally and was insured by "Amtrust Mobile Solutions". Company asked me to pay **% repair charge of the total amount of the product to make a successful pickup of my phone which I paid successfully and then they took my phone. But after few days when I called the customer service to know the status of my claim, they said that my claim has been declined because there has been water found in my mobile's PCB circuit which I am quite sure can't be possible because where the incident happened was totally a dry area.
Even though I made an appeal to them to provide me with the valid reason along with the proof but they didn't even reply for my mail nor even refunded my repair charge and just sending me, again and again, the same mail by mentioning the invalid reason for declining my claim.
Then, I went to the shop from where I purchased the product and from there I got the mobile no. of company's area manager named Mr Sanjay, who told me not to worry about the repair charge because it would be refunded to you which is a secondary thing, but about the declining of insurance he told me to mail by attaching all the arguments done with customer care representative to escalations amtrustmobilesolutions.in and I did the same, but still I didn't receive any response of that mail yet and now when I am trying to call him(AM), he is also just dropping my call without responding to it.
Mobile model - Mi A*
Registered name - Nita Sinha
IMEI no.- ***************
Purchase date - **st of Sept, ****
Insurance company name- Amtrust mobile solutions