Depends where you bought it and the store policy. You asked for a red stone and the store sold you a red stone. The only issue might be if it was not a real red natural gemstone and was a glass or synthetic one instead. What did the gemologist say if it was?
Take the merchandise back to the store to see if they have a return policy. You seem to have gotten what you asked for, i.e. one of the selection of stones you were shown. Until you get some further answers from your gemologist, no further observation is possible here online.