tired of weird calls, didn't say anything when answered

Called caller id said Chicago no answer

At 7:11PM, 08/21/08, i got a call from a "Jack" at (Device?) Distribution Center about a contest I entered called "Grand Sweepstakes Giveaway".  "We have great news for you.  Call us at 1-800-577-3157.  I called this 800 number but was told it could not be reached from my telephone are.  The callerid had 312-238-9447.  I called this but no one answered.