Assuming you have done as "laurarfl" suggesting with temps, hides, and such, I have a question and some suggestions.
First, do you know for sure that it was eating well before you got it?
Something you might try, which has sometimes worked for me: hold the snake firmly so it is not easily sliding between your fingers, close to the head, and gently press the pinky against its nose. Sometime, if you are very still and patient, the snake will open up and take it. You might have to sit and try this for several minutes. If it does take it, continue to hold it without moving as it swallows. The idea is to get the snake to forget you are there.
Another method that often works is to put the snake and the pinky in a small paper sack (lunch size), fold over the top, and secure it with tape or a clothes pin. Put it back in its cage, partially over a warm area, and leave it.
If your snake has only regurged once, thats good. I have one that regurged 4 times before I realized I was trying to feed it again too soon after regurg. It finally ate a few pinky heads, then quit eating again. I got a live pinky and put it in a paper sack with it, and almost immediately the snake ate. That was several days ago, and it has digested it.
To find live pinkies, I would call all the small pet stores in your area. The big box stores don't usually have them. You might also try Craigs List and try to locate other "snake people" in your area. They might know or be a source of live pinkies.
Good luck, and here is a pictue to inspire you. This is from my first successful breeding in 2004.

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Kent