Wireless Accessories

I am writing to letter ID ***Customer bought the tempered glass from us, when we installed the tempered glass, it was 100% perfect and checked by the customerIf it was broken while installation, how come customer paid for a broken tempered glass and left the store without asking to replace
it?? She came back after a while with cracked tempered glass and start yelling at us that we sold her the broken tempered glassWe mentioned her that tempered glass was checked by you before you leave the storeNo one talk to her rudely, all we did, explained her that tempered glass cannot break while pressing the phone's back buttonIf it was our fault, we can gladly take the responsibility but in this case it is not our fault, so her proposal is totally unacceptable, It is not our responsibility how customer use the productThanks Managment