Jetstar Credit Card

There is nowhere online to change your address. So I sent them a letter to update my address.
The letter had my name, date of birth, email address, phone number, old address and new address. It was signed. I sent that over 3 weeks ago - and today I get 2 missed calls from them. Turns out that they still had to call me (from Manila) and I then had to identify myself with Full name, date of birth, email address, mothers maiden name - and then I said - ENOUGH! They wanted to know my phone number or credit limit on the card as well. All I wanted to do was get my address changed - not take out a bank loan - and I had already provided all that on the letter. So I asked for a team leader. She said the same - as it turns out Jetstar Mastercard (Macquarie) needs your full name plus 4 other pieces of ID - even with the scanned information in front of them (they called it an email not a letter).
The customer service manager in Australia (that I eventually got transferred to) told me that they do not accept a written request for a change of address as being an accepted way of changing your address. You MUST call them to update your address.
I guess thats because they dont actually have staff here to open the mail anyway - just people they pay $3 a day to answer calls in the Philippines which passes for customer service.