Complete lack of Customer service

I am out of the country and have been trying for 2 weeks to get assistance in changing the address that my OTP is sent to and am being given a run around. I mailed my prestige banking team for assistance, the change was never made. Then I called in and was given instructions on how to do this. I sent the mail with all the required docs and waited the 5working days and have had no response. I have since sent 2 more emails and waited another 6 days and nothing. This is not acceptable for a Prestige service which I am paying for.