A month without food is not a big deal for an adult boa, but it is cause for concern for a very young snake. Make sure your f/t are warm, and not just defrosted. You can also try dipping them in chicken broth. Stunning live mice is also worth considering.

If worst comes to worst, you can always breed your own rats.

I would be worried if I went to a petstore and they told me their snakes weren't eating.

Also, what's the temp/humidity at in the enclosure? Incorrect husbandry can/will cause snakes to stop eating.