BAD SERVICE

I have been struggling with customer care about my cellphone number. They told me that my number has been giving to someone else. I didn't even receive a sms message or email stating that my cell number is going to be switched off. I have informed them that I am not in South Africa. I need my cellphone number to do banking. Now I can do anything. I won't be able to live now due to the fact that I can't get money out of my banking account. I was rather told I must get a new number. How can I get a new number when I am not in South Africa. I told them that when I was emailing customer care . My reference number is ***.