Fnb non pay charges

Fnb charges are ridiculous why would i be charged R45 non payment for a R29 purchase or R90 for R128 purchase… why is the balance not in real time because this is what causes the issue for years…. Is the IT department sleeping… or they just enjoy ripping us off… whats going on… all im trying to do in this hard financial times is keep my account in good standing but they are discouraging