The plastic anchors can be replaced. They may not hold due to the wind aspects of your installation requirements. I'd recommend more permanent anchors. Try one of the hurricane anchors like a caulk-in or sammy bolt. They can be found at any hardware store. You can contact 'All Points Screw & Bolt' www.allpointsscrew.com/ to review these anchors and determine a supplier near you.
These anchors have a threaded attachment for 'street bolts' with a large stainless steel head that will hold your shutters to the wall against high wind loads.
Hurricane Preparedness Expert
