USELESS!!!!

SO annoyed by this! My debit order has gone off on the 25th as it does EVERY SINGLE MONTH. I call in this morning to get a settlement amount and to my surprise the lady tells me I'm in arears. I inform her that that is impossible as my debit order has gone of already! She assured me everything will be oky. 5 mins later a collections agent calls me to ask me why I've not paid for the month of August and I tell her the same damn story that I DID PAY AND I HAVE THE PROOF OF THE DEBIT ORDER!!!! She explains to me that it should all be fine after 15:00. And she proceeds to SMS me a settlement amount. I them go for lunch and suddenly get a SMS saying my arears amount will affect my credit score. I called in ANOTHER time and spoke to ANOTHER agent and tell her the same story and ask to speak to a manager and what do I get?? Oh we'll call you back in 48hrs. I want someome to call me NOW!!!! I ALWAYS PAY ON TIME VIA DEBIT ORDER AND NOW I GET THIS TREATMENT FOR SOMEOME THERE CANNOT DO THEIR JOB!!!!! Can someone with some brains please call me ASAP!!!!!