Cell C in breach of contract, and NO RESPONSE

So two years ago I had a Smartdata100 contact with Cell C. So the contract terms were One Hundred gig daytime and One Hundred gig nighttime for 24 month. I was upgraded/renewed in July of 2017, to a Smartdata50 contract, but with a promotional deal that doubles the data for the FULL 24 MONTH TERM. Pay the same price of the previous contract, get the same amount of data. Fair right?

WRONG. What Cell C did, is change the terms of my original SmartData100 contract to end that July, instead of the November it was supposed to (21months instead of 24). So I was still paying for 100+100GB a month but my bill was charged with the promotional 50GB too. Not that I ever had a total of 150+150GB for those 3 months. I'm diligent with my data usage. I check my usage and available balance very often and never have I ever had more than my allocated amount.

And that brings us to now. 3 months before the contract is supposed to end, and apparently my "promotional data" ended on the 27th of July. I'm other words,I was paying for 100+100GB a month for 24 months, only to be ****med out of half of it for the last 3 months. Breach of contract much?

I'm terminating my contracts with Cell C. Their disgusting business practices and complete lack of honesty is beyond anything. Not only that, but they now also ignore my complains, never call back.