Parts replace by blackberry service center.

I had submitted my phone and battery in blackberry service center and before i submitted ‎my phone they checked it whether the phone is damaged physically or not and they said the phone was ok nd there is no physical damage. But after 4 days they told me that the battery is physically damaged and the battery is swollen. As the swollen battery comes under physical damage so why i was not informed before‎ submitting the phone
whats the proof that battery is not swapped and there is nothing mentioned on the job sheet regarding this matter? I mailed them so many times but they didn’t respond us.
My Jobsheet number is 8006018936. I can send you the jobsheet also if you want.