I used a mail order prescription service for a while (ExpressScripts). It was awful. They routinely lost, failed to ship, or double-shipped packages, and I got multiple bottles of pills that had expired due to being left in the heat. I, personally, will never trust mail order prescriptions again.
You're judging all the category by the performance of a single provider. I understand that, but I wouldn't discard the helpfulness of this concept just by your experience with one vendor. That's like not driving a car anymore because you had a bad experience with a particular brand.