Treating Customers Unfairly

So I've been doubting my thoughts on and about a certain practice that Vodacom has been subjecting their loyal customers to for quite sometime because I never had proof. I have bought minutes in the past like recently, I would be told I have night shift minutes as well as anytime minutes. On very rare occasions that you would find me using night shift minutes but at the time I want to use it my phone would either chow my airtime or my anytime minutes. I don't understand why the company can be so unfair *********** their loyal customers. I bought anytime minutes after buying airtime 2 days ago so this morning it happened that I had to make a call during night shift. Instead of my night shift minutes being exhausted, it's my anytime minutes that are being used up. So o decided to call in and spoke to a Neo whom I stated my case to and I was told they will send me airtime at the end of the call to help me buy the incorrectly billed minutes from my number. I waited since 10:30am till around 14:44 where I called again to find out what's happening. I spoke to a rude Vanessa who kept jumping into my throat everytime I try to explain what I've been told until I said I wanted to speak to a manager. She then told me that I was going to be told the same thing that she just told me. I said it's fine because I was tired of hearing her lack of listening s****. I was put on hold then after a minute she came back telling me that the manager is on another call and I should wait to be called back. I buy airtime and minutes on my number almost everyday and sometimes they expire without me having used them so the 1 rare occasion that I need to use them they're not available to myself. How is this fair? How do you expect me as a loyal customer of Vodacom to stay with you guys when you are treating your customers like trash. I need an explanation for all the trouble I need to go through trying to resolve 1 small thing and being told different stories. I also need to know why only some of your consultant seem to have gotten training in listening and others don't. Lastly I need to know if my airtime has again gone to waste and no one is willing to replace it so I know what to do with myself. If I don't get a response in the next 24 hours, I will take it that Vodacom does not give a toss about customers like myself because this has happened before and I let it go because I thought I may have used the minutes unaware.