Inadequate service provider

I have been a loyal customer of Vodacom for many years. I have always had 2 cellphone contracts as well as Vodacom insurance for both cellphones. I noticed early last year that I was being charged for insurance for a laptop that I've never had. I enquired with Vodacom and it was confirmed that a credit was due to me. The agent said she would make the request and let me know of the outcome. That never happened. I enquired again this year, in June and July. Again feedback was promised and no one contacted me. Whenever I tried to call, I'd be on hold for anything between 10 to 20 minutes or the call was disconnected and I'd have to explain the story all over again. I have subsequently upgraded my contracts, both with Vodacom. The laptop insurance was stopped but still no sign of a credit. I last spoke to Katlego, after having explained my drama, he assured me that he would definitely give me feedback in 24 hours. It's been about 4 weeks and nothing. I was also automatically charged for cellphone insurance for one of the new phones, that I did not request, which I then also had to cancel. I would like an agent to contact me with feedback, immediately, confirming that my credit has been processed. Furthermore, I am utterly disgusted by the service that Vodacom has rendered to me, a loyal customer.