Shocking Service from Discovery Card

I have been a Discovery long time client (both medical aid and credit card). I am currently working in the UK so changed my OTP from sms to email while I was there in January. This involved a long phone call but was reassured it was done. Back in the UK tried to make a payment and still sending me OTP to sms. I have sent several emails explaining it was not successful and could not be contacted on my SA number so could either phone me on my UK mobile or my email but to please fix. I have not had the courtesy of a response 3 emails later. I will be paying my card off and just using another bank's credit card that wants my business. Just a warning for others who are contemplating taking out a credit card with Discovery the service is terrible.