Poor customer service

I have a contract with Telkom (Wi-Fi router) and it reached it's 24 months in March. I got a call from selldirect informing that I am due to an upgrade and they can help me with it without me having to go to a Telkom branch.

I was on a 20G contract @ R439 and got upgraded to 40G and the lady said I'd just have to pay R10 extra for that plan making it R440. But when I checked my bill, it's up to R557.26.

The simcard is not activated so I went to telkom and they said they can't pick up the upgrade on their side and that I should call selldirect. I called on 30/04/18 and the lady said she'll email telkom and the simcard should be activated by Friday (04/05/18).

The simcard is still not activated and I don't know why I'm paying so much money.

The old contract sim card is still activate with the 40G plan.

This is really an inconvenience as I have exams to prepare for and I need to be online most of the time.