billing before time

My name is Zinhle I'm currently paying for truworths and rcs with easton berry. I'm getting paid on the 15th of everymonth if it falls on weekend or holiday I get paid friday before. This month 15th is tomorrow which is monday but I got a debit on friday and the bank reversed it because there was no sufficient funds in my account. Why was the account debited before I got paid now I had to pay charges for these returned unpaid debit orders which is like R100 each. Someone deposited money in my account and I couldn't withdraw as money was took by these unnecessary charges you caused in my account..