MTN slashes my benefits by more than half at 73% of my current payment

MTN slashes your benefits with one email. I was sent an email saying that I would be put into the Yellow Plans Core package at R175 per month. What they do not tell you is that your data will be reduced from 12 GB to 1 GB and your phone minutes from 125 to 60 minutes. I currently pay R240 per month for 2 numbers to get 12GB per month and 125 minutes per month. My contract expires in the following year. So in the middle of my contract they break the arrangement unilaterally and just inform me that they are reducing the data and minutes I get, in the middle of my contract. This is not way of doing business !! I am considering canceling my contract and going to another provider !!