Lenovo — mine lenovo zuk z1 device warranty related irresponsible response from customer care

Address:

Ahmedabad, Gujarat

Hello
I've purchased a lenovo zuk z1 mobile just before 10 months ago
Now suddenly i got it off
And then i went to customer care at ahmedabad
And at there assistant people has said that your mobile if accidentally water damaged
I've refused but they have repeatedly said that to me
Then i've said them to repair/fix it.
They have only turn it on
And now they are asking about 450 rs.
And they haven't repaired mine finger print sensor and home physical button and for repairing it they are demanding 6000 rs
How can they demand that?
Same case of mine friend they have resolved in free
And they are demanding from me
And they are saying that i've done some fluid damage. There is nothing fluid damage and if that's possible battery liquid leakage then is it mine fault that lenovo people have created a non removable battery mobile?
They are demanding a money so according to them they should have take mine permission before fixing the mobile design
Last thing they are saying that i've damaged the mobile by battery liquid damage. Then you (Lenovo) people answer me that is it possible to remove a battery from non removable mobile and put it aside at home???
Hope for the help...
Thanks