Migration issues!

In June 2016 I started a 24 month data contract ( ********** 939). In March 2017 I migrated upwards via the call centre, without getting a new device. The device that I got at the initial contract period is being paid for (R120 pm) on top of the new data tariff (R399 pm). According to Telkom's own Terms and Conditions:

TELKOM MOBILE SUBSCRIBER STANDARD TERMS & CONDITIONS

'5.5.2.2 any Migration will not have the effect of creating a new agreement, save that the parties will conclude an amendment to the Agreement which details the revised Mobile Goods and Mobile Services and the associated Tariff Plan, selected by the Subscriber;; and'

It is now close to the end of my June 2016 contract period and I phoned to find out when I can cancel the contract, only to be told that I can only cancel in March 2019 due to my migration in March 2017.

I am very unhappy about this. The only reason why I did not accept a new device is because I did not want to start another 24 month period. The month-to-month sim only price back then was R399, while the 24 month device included was R449. Hence, I am technically paying month to month rates.

If Telkom changed it's T's&C's in between then and now, I don't think they can force that upon me after an agreement was made?

According to the very very indifferent call centre agent, I will have to pay R800 + one month subscription to cancel the contract. This I find ridiculous. If this is Telkom's game then I intend to warn everyone to stay away from this company.