MTN USELESS CUSTOMER SERVICE!!!!!!

What must I do to get MTN to change 2 simple things on my contract????? Change my Debit Order Date & my email adress.... How difficult can it be????? I have logged numerous requests and even called the helpdesk several times..... But in true South African Fashion, EVERYONE I speak to at MTN PROMISSES me they will get it resolved.... BUT NEVER DOES!!!!!!! I have now gone to the extend of canceling 2 of my contracts with MTN.... Im about to cancel the 3rd if this is not resolved ASAP!!!!!!!