Terrible customer sevice

My Vodacom data contract is complete within the next week. I want to cancel do to extra billing caused by a Topup account being changed by Vodacom without authorisation. Tried to phone the Vodacom retentions call centre but could not get through. Went to Fourways Branch to try and cancel my contract and was told they could not do this at branch level. So phoned the call centre again, when I finally got through was told the system was down and they would phone me back. I never got phoned back. After a day tried the call centre again after 30 minutes still could not get through. Unfortunately I have found this to be typical Vodacom service.