RUDE AND INAPPROPRIATE MANNER TO ADDRESS PEOPLE

So an agent from MBD by the name of Nothando LG1 calls me on Saturday with an unknown number and the first thing she requests is that I confirm my ID number of which I refused as I had a few questions to ask myself, the agent was rude and the manner in which she spoke to me was uncalled for, She told me my question was irrelevant and I needed to pay my account thats the only thing that mattered to her, this lady was literally screaming and speaking over me, i really did not appreciate her tone, I called back with my fiances phone and asked to speak to management, I spoke to a gentleman called Thato, who told me he was a supervisor and would escalate the matter and get back to me, it is thursday today and I have not received anything from MBD regarding my complaint-instead they have saved my fiances numbers and have started spamming him with sms' without his consent-who does that??? I feel harassed, disrespected and treated like a piece of trash by these people, I pay my accounts properly and if there is an account where I need clarity before I can make payment I expect the said consultant to assist me. There are ****s doing the rounds in South Africa and to just supply your ID number to an unknown number is a risk. I hope this gets escalated and is sorted out because this cant be life and a way to treat people!!!