How to handle frequent fraudulent orders affecting my sales?

[LilJH]

Recently I keep receiving several frauds orders from xx NW xx st, Miami. That's fine, I can cancel these orders and just ignore them. However, the problem is I only received 2 normal orders within one week! Usually I can get 1 or 2 orders daily. Sessions are same. I don't know if it is caused by those frauds orders or just my store problem. Any one has similar issue?