Trip to the bank

After a confusing phone call with the Nationwide, who seemed to have no idea how to provide me with a certified cheque, bank draft or money order, I was told to visit my local branch who would be able to sort me out. For the privilege of spending my own money I have been quoted a £12.00 fee and about a week to wait for the cheque to be delivered. I'm not convinced they're even going to send me what I need; when I asked the cashier the difference between a normal cheque and a certified cheque the answer wasn't exactly forthcoming.