I had been ordering the simparica trio. I noticed that there was a chewable version but I did not realize that it did not include heart worm protection. Instead of giving me a heads up (because I really didn't know the difference & I would expect the employees there to know) I was allowed to change the order easily (which I appreciate) however I was not warned about the difference. Now I can't get my money back & my software doesn't have protection against heart worms. I am a graduate student so I can't afford to just throw $50 of medications away/donate/etc.