UNPAID DEBIT ORDER DUE TO SMALL EXCESS

I've been a customer of FNB for over 20years, salary paid directly into my cheque account. Never defaulted or was in excess of my account until now. Due to Covid-19, I overspent on my grocery budget and have gone in excess of +- R1200. I subsequestly deposit R940.00 bring my balance down below R300.00 They actually UNPAID a policy debit order of R303.50. Due to unpaid fees my account is till in excess of R144. I called FNB this morning asking to reverse the unpaid and was told that it is an automated process and unable to pay the debit order. What happend to "How can we help" Really FNB shoul dchange there slogan "WE DO NOT HELP LOYAL CLIENTS?" My excess was such a small amount and yet they cannot assist., Will definitely be looking at changing Banks