Alien object in food and restaurant refused to take ownership

I ordered a meal that I’ve ordered twice before at the establishment only this time to be met with a piece of string and when I informed management namely Tyrone and Tinashe they handled the situation with inexperience and insinuated that I wanted a free meal and Tinashe also said I shouldn’t embarrass him?? WHAT?? That is no way to handle a situation like that. If a meal comes with string you must warn patrons of there was a mistake at the kitchen you apologise and not expect patrons to pay for that mistake as it could have been fatal then what? I’m never going to that place ever again and I’ve advised all my friends to do the same.