No service at all

Last month I was charged overdraft fee and it was claimed I had insufficient funds but I see the charge is there again. What is the excuse this time around? Same goes for std bank mobile, I have been charged and no airtime being loaded, last month I was clear that I am giving notice and no airtime should be loaded manually and was promised there wont be any charge as the last one would be seen as the final one, again, I am charged.