That's part of the headache with f/t, and it is a reality that you will have to sometimes throw away the food.

If it goes on for much longer, you may need to seek a Live alternative. Start looking for some local mouse or rat breeders, or Petco sells feeders.

I've had some incredibly stubborn snakes when I was doing the f/t thing...and once I went back to Live, almost every feeding night is 100% successful. All but 1 is eating right now ( eggs )