Credit card OTP to be changed from sms to email

I called the credit card department to change my OTP from sms to email on my credit card while overseas. They said they cannot assist I must call internet banking. I called internet banking and was on hold for more than 20 minutes. They then said they couldn't assist and that they will explain the situation to the credit card department before transferring me back as they must assist. When I spoke to the credit card department the internet banking department did not do as they promised and had not spoken to them. The credit card department said they couldn't assist and transferred me to internet banking ***** department. The internet banking ***** department also said they could not assist and wanted to transfer me back to the credit card department. I was on the phone for more than an hour and got no where. This is unacceptable!