Payment not reflecting

Can someone please explain to me what the hell is going on in that company?One agrees to make arrangements for payment but 2 weeks before due date you get calls non stop reminding you to make payment and when you finally do they tell you they haven't received it.Nothing is working,the reference number at Standard bank branch,the online EFT link,Easy pay method at checkers!!!!I tried all these options and emailed proof of payment but I'm still being called everyday to say I haven't made payment! The agents are so rude!! One specific agent CATHERINE is ****** rude and yes she is clueless as to what is going on in her own company with regards to technical issues relating to payments!!! I have had it with these company!!!!