Help with Nigerian bank?

Ok i have a job interview for a company bank in London being worked out through a bank in Nigeria and they will pay me $200,000 when i get there, i found the job in my email address to me and i so far gave them my bank account number and they took $4,000 out of my account because they said they needed the money to send me a plane ticket so i can come but i havent recieved the ticket yet and its been 3 weeks.. I think it should be coming any day now.. What do you think i should say to get the Job??