Pathetic service

I have app**** for Finance and was declined due to mtn stating my account is in arrears since July but the debits have been coming off my account every month without fail , I am highly upset as when I called them they said it's up to date but can only give me a letter within 3-5 working days , I dont see why I need to wait because my account is not in arrears and has never been and I cannot wait so long for a stupid letter