Poor Service and Overcharging

The most shocking and disappointing service or non service. You have been overcharging my account for months. When I realised I called and was treated with such disrespectful behaviour. I am still waiting for a supervisor to call me back to explain. Today I did a follow-up call and was left waiting for 7 minutes to speak to a supervisor before being cut off. How is it possible that you can simply increase my account payment and add additional feature that you charge for without my consent. I want an explanation and full refund.