Disgusting Service and refusing refunds

I called Africa mobile in early in July to change my bank details, they sent a mandate, they debited my account twice, I reached out on the WhatsApp line, I was told I can't get a refund they will just hold next month's payment, I asked for an explanation as to why there were 2 mandates sent and I would like the other one cancelled, I messaged at 8:51 am and only got a response at 4 in the afternoon, I then called the customer service line and the advisor told me I can get a refund but she needs to pass it to somewhere else and then she disconnected the line on me, I then called again today and was met with the rudest customer service agent I have ever dealt, taking into account I am a customer service manager myself, she told me she cannot give me a refund because she's just a call centre agent and she doesn't care where I work, the 2nd time I called I got through to her again, surprisingly, I requested to speak to a manager, she told me they do not have one, shouting at me on the line, and dropped, I called through the 3rd time, and you wouldn't belive I got through to her again, and told me again there is no manager and I can go to the ombudsman she doesn't care, I am utterly disgusted by the lack of service delivery and the type of people they employ in their customer service team, how these calls are recorded for quality and training purposes and these types of people are still employed is beyond me, firstly I never asked to be debited twice, so why am I not entitled to me refund, I can't wait for my contract to end, I will not recommend this company to anyone, it's really a joke of a company