Struggling with help

After sending numerous mails to one of the premier bankers, they just keep passing the buck and refer me to different departments. I am not in South Africa anymore and can not change my OTP number to an international number on the website. The premier banker sent me an email that they have been trying to contact me to no avail. They phoned me once and I couldn't hear anything. Phoning once is not to no avail. This premier banking service is useless and does not live up to the promises made when signing up. If there were any other half decent banks available I would switch, but the hassle is also too much. All of this hassle just to try and change a phone number.....