Your way of work is irrational.

First I want to know how do -you let the customer pay first for the service while knowing that the windscreen will be the issue ? And then tell us to fix the problem so we can get the certificate who has the money right away to replace the windscreen so that means i am going to forfeit my money ? Why you don't train your managers and staff to alert the customers that the test may fail before paying ? Some customers its their first time they dont have information about this so please be kind and nice before taking people money.