Have you been encounter this situation? How you reject? What's the respond from the company? Izzit possible to take back offer after you reject it?

I did faces same situation as mentioned... but somehow... i didn't care
then wait for next round...... shit... same thing happen again... all company interview comes in together but respond at different time... tooks time to compare those job...
Whenever I said SORRY coz bla bla... the other site will seems angry lo...they will raise up thier tone and say: NO PROBLEM!
one of my friend meet the interviewer in a jobfair... and he look at her with wild eye some more.. coz she rejected the offer after she considered...