Terrible service experience

Terrible service experience by RocoMamas Melrose Arch store. Requested a glass of water but sent it back because there was an insect in it. The waitress brought another glass of water in which I found another insect. The waitresses response was that I was wrong as she inspected the glasses and found no insects even though I was holding it in my finger. While the manager apologized profusely I can't believe the attitude of the staff!!!