Upgrading of a Cellular Contract

I am trying to upgrade my cell contract which is an absolute nightmare. The branch in Northgate claims online deals can only done online, go online select the handset, the colour and the package and that's that, you cant continue any further. The sales call center on 081 128, I think is on leave today. Customer care on 081 180 says online deals are only for new contracts and not upgrades. Alternate number given by the call center agent ***, nobody answers. if Telkom is a company that responds then contact me as i want is to upgrade my contract to a deal advertised on your website.