Discovery Bank Wake up!!!

Whilst the banking division was being done by FNB, it was a pleasure dealing with them. Since then, I have not been able to use my account... their cellphone banking app does not let you sign in. Every time I speak to them they tell me what the previous person and previous person told me to do. One says my cellphone is linked to another user??? I have had this cell number for more than 12 years. Then the next says that my email belongs to someone else..... I have had this email address for 21 years??? Then someone says they will put me through to someone to sort it out...... Then I get cut off, next month they phone me and a repeat of the same discussion is had.