Telkom giving very mixed messages...

I currently have a "unlimited" LTE @ home data plan with Telkom which I have had for over a year and the service is fairly reliable and works well most of the time. Previously I was able to upgrade my plan to a bigger package and just pay in for my modems cost for this early upgrade. Now I went to the store in Eastgate and enquired if I can upgrade to the Terabyte plan, the sales clerk said yes you can, but we don't have that package in store yet so I need to phone in. I phoned in and the call center was closed so I sent a web enquiry, I now received a message saying I'm unable to upgrade at this point in time. I'm very puzzled with what is going on, as I was considering canceling this entire contract due to the cost of it and the amount of data being received on a monthly basis. As your competitors like Rain are far more affordable , faster with far superior soft caps. Please advise Telkom as I find myself being rather puzzled about this at present???