Unable to upgrade

I went to a Braamfontein branch to upgrade my contract and I was told that I couldn't upgrade to a voice contract since my current contract is a data contract. I was given the retention departments numbers (809 and 8080 to call for assistance and advice on how I can upgrade. I can't get through to a consultant since the number keeps disconnecting after holding on the line for 2minutes.<br> <br> At this stage, I would rather cancel my contract and go to a competitor. Too much stress to upgrade.