billboard

at about 6.30 pm on 4/16/08 i posted a messg. with my bux that was to run 24 hours
and i see that at 8.00 am on the 17 th. its gone ?i wanted to post another one today for 2 days with my bux but when i went to do it it said the billboard was being used by some else for 30 days so i looked at the bux redemtion screen but it does not show the billboard being purchased? and why didnt i get my 24 hours? i paid for them