Hrm, well a lot of less appealing custom prosthetics take considerably over a month to receive once ordering, and costume/Halloween applications are the majority of their business, so it makes sense. While you might consider your need for a medical prosthetic more pressing than an Avatar nose or Freddy Krueger face, it's the high volume of costume orders they get that allows them the means with which to develop and produce medical prosthetics, which doesn't make up much of their revenue as I understand it.
From a business standpoint it's only logical that Halloween orders take precedence, as they're time sensitive and useless to most customers after the holiday, whereas we'll still have the need in November on. I can appreciate being frustrated of course, I however am just grateful that they even offer such products and listen so well to requests and feedback from clients about their FtM products. Other 'FTM specific' companies like Lolajake aren't nearly as customer focused or receptive to criticism/potential improvements.