Over charged

I have been over charged each month for 3months now. I have not used the line since November 2014 as I'm out the country and working on a ship. My contract says R189 per month which is what you have always charged me and now you have suddenly changed it. When I queried why you refuse to allow me to give permission via email nor give someone else permission to check into my account. I can't take calls here nor make them to call centres as slow and insufficient as yours. I'll be on the phone all day on international rates which I refuse. We have email for a reason. I need you to explain why you over charged me as well as set it back to its default and refund me or else cancel my account. <br> <br> My number is *** and I need it sorted ASAP. I've emailed multiple times to Lerato as well as cell c them selves. <br> <br> I need this situation fixed now. Stop over charging me or else cancel my account <br> .I will be putting my boyfriends number for you to contact, he has permission over my account as I stated in my emails.