Onsitego — complain about my samsung j7 prime mobile

I had taken extended warranty of onsite for my samsung j7 prime and in the very first month of extended warranty the display of the phone got off and was not working although the incomming calls were their with ringtone working, for which we registered a complain, the phone was dropped at croma store on 24.11.17 from where it was purchased and till 30.11.17 the on line check was showing that your phone is under diagnosis at service centre and the expected date is soon to come.
On 2.12.17 i received a mail that your phone is liquid damaged hence we will not allow any claim.
This is cheating a customer as keeping the phone under your custody for 8 days and saying liquid damage which is definately done from their end and giving an estimate of rs 11000/= whereas the present phone cost is 13500/=. I will go to cosumer forum.