Customer services can't seem to understand English

I have written to customer services regarding my account numerous times because the latest statement they sent I cannot open with my ID number and I cannot pay my account as it says invalid reference but its been a beneficiary on my account for years... I try tell them and each time they tell me password is my ID number.. it does not work amd I cannot pay my account via eft. They have given contact details for rcs but they do not respond to Amy of my correspondence