Upgrade from 100GB To the double data 200 GB

I'm paying R 1049 for the 100 GB LTE, but I want the double data of 200 GB it's a simple upgrade. But know not to Telkom they want to charge me a penalty for upgrading to this. Last time I went from the 60 GB to the 100GB and got billed a penalty of R 950, now Telkom wants to charge me again.

If my contract runs out I will cancel all my Telkom contacts with them.

Useless with the letter U