POOR VODACOM SERVICE

Poor Customer Service, they called me for an upgrade, the agreed amount was R1640 and then they debited R2464, I have called numerous times to try and sort this out, and evertime the transfer me, no one can help me, this is very bad service, because I didn't sign or agree to this amount.... I would not refer vodacom to anyone... and will be moving soon to another service provider!!!!!!!