Rubber band in MCflurry

I bought an oreo Mcflurry at the Macdonals near east rand mall this afternoon on my way home from work as i was reallt craving it. As i was eating the icecream, as i scooped out some more this long black thing came out. I thought it was like chocolate as it was covered in ice cream, as i tried to chew it it felt and tasted like rubber...i took it out and wiped it clean and it was like a thin firm rubber band snapped in half... i didnt even eat the rest of my ice cream.