I second Ballz technique it work for me to make the switch to rats....
Second, its October now, if you done your research you would have known from oct-jan(months vary according to the snake) and they begin to fast.
Thirdly, why on god's green earth did you leave a LIVE animal with an animal??? Much less a 1200$ animal???? Maybe you haven't but I've seen firsthand snakes litterally disembowled, broken jaws, scaring, kinked tails and yes even animal on its way out due to poor keeping. If the snake will not eat, there are more ways to entice a stubborn snake to eat before jumping to live.
There are many MANY books, caresheets, and tons of reptuable breeders that can give a wealth of information.
Fourthly, here's couple techniques I've used for my BP's and more often then not it works for me. First if you haven't tried it, BallZ feeding tactic is almost simlar to what I've done in the past and also has worked for me.
Feeding tactic 1.
Prekill a mouse/rat and soke it in warm chicken broth. If trying froz make sure the animal is completly thawed out. More often then not I usually get a strike.
2. The paper bag
This is simplistic. Prekill a mouse and place the snake and the mouse/rat in a paper brown bag and put a piece of scotch tape or somethin to hold the flaps in place when foldin the bag. This is done so its a smaller space for the animal to "smell" its prey and its dark. BP's are timid.
3. Try feedin at different day cycles-
I have a male that eats mid afternoon 4-9 and a female that refuses to eat all together unless the room is still and dark. Makes it hard sometimes to walk around, lol. She's gettin better where as, I can leave the light on, til she strikes and coils, after that if I dont leave the room with her frozen rat and turn off the lights she get spooked. She also seems to prefer feeding from 10-12 midnight.
4. Wait the snake out an be patient! As this is very hard for beginers, more often than not, the feeding can be more taxing on the owner and less taxing on the snake itself. Try different tactics and everyone has a different way, and try 1 say, lets say Monday you try and feed. Nothing. Try again 7 days from then and repeat. Repitition is key especially with balls.
Also, I dont know how long you've had this animal or what your current heat and humidity is at on adverage not to mention what is your setup for this python. If its incorrect temps, it may be too cold and the snake's metabolism has slowed down, which would also cause it to cease to feed. Temps should be 86-92 with a basking area of 95. Humidity should be 50-60%.
Also, I'm assuming you handle your pastel alot cause you think it looks cool and its pretty. If that is the case, STOP THAT! If you haven't gotton it to eat, handling is going to prolong it's feeding schedual ALOT!! Due to severe stress.
Good luck and feel free to email with questions
Jess Bruce