Poor Customer Service!!!

I have a personal loan with Nedbank and due to unforeseen circumstances I have missed 1 payment from the time I have been with them bearing in mind I am with them from 2016! I have received a call from an advisor by the name which I believe is Ernest and he is very rude! No telephone etiquette s****s, unprofessional and questions myself in a rude way to ask what's going on and why I missed a payment? I think Nedbank call centres should be reviewing their advisors calls and making sure customers are treated fairly! Yes I understand I have an agreement with Nedbank but it does not give anyone the right to speak to a Customer the way I was spoken to today! I am not saying I am a saint and I wasn't rude back, yes I even swore and dropped the call but it was simply out of retaliation. I would like to be contacted by a manager ASAP via email as I want to keep records of the conversation between myself and Nedbank!