First off - ensure that it's conditions are perfect
keep it in a small enclosure no more than half the length of the snake long and 1 foot high. Provide a TIGHT hide box at each end of the enclosure. Make sure the temps are right (for a non-eater, you can try going a little hotter - 30 degrees C or so). You might also want to try coverin 3/4 of the exposed glass/plastic of the enclosure with newspaper to block out movement or light.
There are literally tens of things that you can try:
1. feeding at different times of the day/night
2. warming the mice to different temperatures (i think that the core body temp of a mouse is about 30 degrees C)
3. braining - cutting the scalp of a mouse and squeezing the head a little (the smell of brain is quite strong and sometimes figures a feeding response)
4. trying different sized prey (from pink mice to weaner rats), remember: whilst the generally recommended size is 1 1/3 times the size of the fattest part of the snake, it can quite easily swallow something 2 or even 3 times its diameter and digest it.)
5. cut the mouse's gut (messy, but worth a try)
6. warm the mouse in a bag so it doesn't get wet
7. warm the mouse in the water so it gets wet
8. try wiggling the mouse with tweezers
9. try putting the mouse in the enclosure without disturbing the snake (let it find it without drawing its attention to it)
10. try scenting a mouse with chicken broth
11. try scenting a mouse with skink urine/poo
12. try blocking the snake in total darkness to let it relax
as a last resort -
12. try holding the head of the mouse in the snake's mouth for a minute or two, then put it down softly and it may proceed to swallow (it may just spit it out)
13. forcefeed the snake (put the head in the snake's mouth and slowly but surely massage it all the way down into the snake's stomach)- be sure to have an experienced keeper show you how to do this first - it is quite dangerous
Keep in mind that your spotted can probably go at least another 3 months or so before any cause for alarm (disclaimer - can't really tell without a photo... just ensure the spine isn't visiblely protruding and the skin isn't too loose). Sometimes snakes just go off feed (whether due to the weather, season, or just plain frisky
)
Don't stress about it... and only try to offer food every 4 or 5 days or so. Good luck. Smile.
Aaron.