Over charged

I have and outstanding balance account with African bank an became retrenched a few years ago I issued my unemployment documents such affidavit ad advice by African bank consultant at the time and to all my other accounts and strangely they did not receive my documents stating I am unemployed eventually when I found a job I made arrangements of a small amount which was set up as a direct debit monthly to the amount I can afford a year ago African bank decided with out my authorization to debit my account twice a month. I have incurred charges on my statement for phone call charges and sms charges but that phone number was no longer in use at that time and according to statement dates infact I did not have a phone at that time of charges . I paid or still am paying insurance that has not covered me at the time as I was unemployed for almost a year after I have notified use but still today and additional amount is being charged to my statement every month I fell that african bank has rob me top the max they HARRAS ME EVERYDAY CALLING ME UP TO 5 TIME A DAY AFTER I HAVE PAID THEM I AM DISGUSTED THAT I AM KNOW PAYING WAY OVER MY AMOUNT AGREED AN CHARGES OF NO FAULT OF MY OWN AND ISSUED MY DOCUMENT STATING I AM UNEMPLOYED AFRICAN BANK ****** ME.