I agree- his emails are read/filtered and reviewed for customer service issues. That store has very poor management to automatically accuse you of doing something to the phone. I would feel offended too. Also, how can they 100% prove your phone was made with no defects?Write an email to Tim Cook! You're guaranteed a response from one of his henchmen.
In my opinion- Even if they had other customers ruin their phones they can't jump to conclusions that everyone is the same.