Salt Packet in Chicken Burger

Went to Nandos on old Main Road in Pinetown this evening and ordered 2 burgers, one chicken and one veggie burger. In the chicken burger at the end my mum found something inedible on a last bite and when she took it out of her mouth she discovered a salt packet that was in the burger.

I find this unacceptable because it shows that no care was taken in preparing the food that we ordered. I do understand that the store was busy but it could have easily been something dangerous and if she had choked on the salt packet this would have been fatal. I do have pictures of this if you would like to see them.

Can you please address this situation because I just find it distasteful especially for such a big franchise, especially because we buy there so often.