Hmm... Call around to all your local places and ask about same-day return policies if your animal doesn't take the feeder. It's kind of a long shot, but the place we buy prey from (Pet Supermarket; they have locations all over the South if that's an option for you) will actually take them back if they aren't eaten, so it's not totally unheard of.

Did you purposely skip 3-4 weeks of feeding, or has she been refusing food? If you purposely skipped that much, go ahead and see if she'll eat. If she's been refusing, maybe wait for someone with more experience with fasts to chime in or post a new thread about how to handle offering food during a fast. I'm lucky in that mine has never skipped a single meal, but that means I don't really have a lot of advice for offering food during a fast (other than 3-4 weeks isn't long enough to start worrying).