Disgusting service

I am very much angry and disappointed at finchoice. I have a 24 month loan which debit 1600 per mnth but this month I noticed that my account was debited with R2300 when I called finchoice to fund out why I was overcharged they told me it because I had purchased airtime and electricity. I told them that I am using a business phone which does not even allow me to purchase airtime, I have to wait for month end to get minutes and data from my employer. Aa for electricity i dnt purchase electricity using a finchoice app. They promised to so an investigation on my account and that they will get back to me. After 5 days of their silence I called again I was told to email an affidavit. I am always the one who calls to make a follow, what makes me more furious is that yesterday I was told that the ***** department did received my affidavit but there is no note made, so they sent know what is happening. Tell me what am I suppose to do now if you tell me that you sont know what is happening? My cellphone number is ***