Items placed in food to harm customers

My mother bought wraps from Kauai at Harvest place in Glen Marais , Kempton Park. After they receive an incorrect order and then getting the correct food al the people working in the restaurant looked at my parents as they started eating then my mom found a ***** and steel wool inside her wrap. She took it out and gave it to one of the people which now denies that it happend. So Kauai i demand an explanation and an outcome regarding this as this can seriously cause harm to your customers.

How many people have they done this to in the past ?