4 cards in a row dont work

My debit card stopped working in ATM's about a year ago so i drove to the nearest branch and got a new one.... after 2 days this one stopped working. Bear in mind i live in KNP so my closest standard bank is an 8 hour return drive which i now did again. Every time i go to the bank they say, ' theres nothing wrong with your account or card...' so i take them to the ATM where as soon as my card is inserted shows an error and spits it out. Anyway, a year and 4 cards later and Standard bank still cannot tell me what is wrong with my card, accordign to every branch there is no problem..... when i cannot access my own money, there is a problem.