Thanks for your feedback Derek. Unfortunately, it's not always possible to install security screws as the suitability depends on the nature of where the grill is being installed. Your installer was Barry who has 25 years of experience in Window security and will give you a call today to explain why he took that decision and run through the other features of the grill and additional steps that he has taken to prevent it being removed, hopefully, this will resolve your concerns. Thanks Again, Claire (Commercial Manager)