Balance transfer Amex to Santander

A question about : Balance transfer Amex to Santander

I want to transfer the outstanding balance on my American Express credit card (British Airways American Express Premium Plus card) onto my Santander 123 Credit Card (ie. I want to pay money from Santander to Amex).

I tried to do this using Santander online banking but came up with a technical error. I then called Santander but I'm not convinced the person I spoke to knew what she was doing - she asked me for the account number and sort code (for a credit card?!) and then fobbed me off with some excuse about a security check. She said I should call American Express because my name and address don't exactly match up. This sounds like a made up excuse.

Any ideas how to get around this?

I've heard things like doing it online but putting a zero in front of the card number to make it 16 digits. Does that work?

Best answers:

• I'd try calling Santander again first, hopefully you'll get through to someone more competent.
  Here's a similar thread I found
• Ok I called Amex to ask about a sort code and a/c number and they told me to use the same details as given in the thread linked to above. Called Santander back and to their credit they've now processed it and it's all fine.
  Seems like it would be best if Santander knew Amex's details.