I have applied for a exam 1/4/2009, I choose the exam date is 11/04 and they confirmed that I can take exam on that day, but they sent me a email said they would change the date to 18/4 three day before the exam, but I can not do the exam on that day and I can not wait as well, so I asked for refund, but they refused. so what should I do, where I can complain?