Account Transfer...

I never have problem doing account transfering until yesterday or today?Never mind,tell you the story.
I lack of hard cash in my wallet so I have to do account transfering to Yong Jie for teh KTV session.He gave me the account and so I did the transfer.Then when I log onto net today,he came to tell me that he have given me the wrong account to transfer to.So I call the POSB Hotline to see what I should do.The person told me that I should go to the nearest bank tomorrow to cancel the transfer and claim back the money.I also heard from Yong Jie that he already ask quite a number of people to transfer to the wrong account he had given.OMG! Total amount is like 500++.