Terrible customer service from vodacom

This is the 4th time that i am writing about the poor service from vodacom. Vodacom has been over charged me on my contract for 18 month and refuse to rectify the issue. Very poor service. Please stay away from vodacom. Customers rather move over to MTN, cell c or even telkom and im sure they will get better service as you can't get any worse service than vodacom