Rejection of a claim with no diagnostic check

I got a call from an assessor on Friday to advise that water damage on the car is caused due to wear and tear as the battery was leaking fluid. No diagnostic check was done on the vehicle and I told him on Friday compile a report on your finding until now nothing has been said after I advised him to take the vehicle to Auto Body in Brits to advise why the vehicle was cutting when y mom drove it. From last week Tuesday the veh has been at Smd no response what so ever or any update to my mom. I will be approaching Osti regarding this claim as it was said on Friday its not a covered peril wear and tear with no diagnostic check was done.