poor service

I have 9 years with this service But the year I have decided am terminating the contract with them. The service is so poor From client service and all, I have been billed ridiculously on data and air time and when you want to lodge a complaint you are not given the appropriate line to complain. A lady from them called me about an upgrade and when I told her am not interested I actually want to cancel the contract because am not happy about the service she could not even explain to me how am being billed. I feel vodacom is really robbing me and I need to port after 9 years of having a contract with them