Angry and Frustrated customer

I took out a contract with mobile plus because they said that they are partnering with MTN it was a verbal contract. I like took a Huawei Ascend G6 for R89 per month which was one of their summer promotions only to my suprise when the debit went of they took R280 from my account for the last two months now I'm contacting MTN to give me some answers seeing that Mobile plus tells me that MTN is aware of the over billing situation so calling MTN I get ref number upon reference no saying that my problem has been resolved but still to date my money has not been refunded. If I call mobile plus for the last two weeks before I can explain my situation they tell you that the system if offline so she won't be able to access any information I am seriously angry and frustrated coz I never gave MTN or Mobile plus permission to deduct R280 from my account all I need is to be re emburst or I will make sure I have on mo e.g. in my account by the 15th of each month and they can rather blacklist me this is how sick and tired I am?