Unnecessary bank costs

For the past 3 years while dealing with teljoy every year I contact them to confirm that I do not get my salary early in December but each year they do a early debit while there is insufficient funds in my bank account this in incurring unnecessary banking fees for debit unpaid I do not understand why I take time out of my busy day using my airtime to contact them and make arrangements for payment on the normal date but they still try to take money from my account I have currently lost R365 this is unacceptable and needs to be fixed