Unprofessionalism and inconsideration

I have been paying my Standard bank account without fail until I only realised that my debit order has stopped.When i called them today I get told by some Lerato girl that I have asked for a set off.1stly i dont know what a setoff is,she tells me that it means I called Standard bank to arrange with them that I will pay them directly.How can I do that when i have a debit order arrangement that I have been honoring without fail.You guys are not going to mess up my records like that,you better fix this mess