Manual Payment made but debit order done on my acc

I have had enough with this company. I have been fighting with them since the beginning of this year. .I made a manual payment into their Absa bank account with the correct details. TThey had the nerve to go and debit my account whereby there were no funds in the bank account. NOW I want to know who is suppose to pay for the ****** bank charges???? The reason why I f...k make manual payments is because since january they decided no to debit my account on the agreed date, I left the money for about 5 days in the account and they didn't bother to damn! Take it. I had to inconvenience myself and go to make the payment 5days after my payment date. This happend on two occasions...now that I go and pay them manually they get up to **** on my bank account. I dont know is this company ran by illiterate or stupid people....I demand a refund for this ****!!!