Sims 3 Late Night disc not working!!! Please help

I've been trying to figure out why my Late Night disc has not been read in my computer (Mac). I am very worried since i spent around $35 on the disc and now it isn't working. I am guessing it is because it is a bit scratched but I don't know if it won't work if it is scratched. Should I buy a new disc? Should I report to the place I bought the disc from? Please answer as quickly as possible I have worked on making my Sims 3 work all day (literally). Anyways please help.

                                                                                                                                                                                               Thank you,

                                                                                                                                                                                                       Nini Poods 😉