Axxess charging me for something I did not agree to

These people are changing my package from 100GB Cell C LTE to 20GB Cell C LTE. Firstly they are moving me from Cell C to MTN because Cell C cancelled their 100GB packages. How is this my problem? This means that I will have to start my 6 months clawback from scratch when I am at the end of it. On top of it all everytime I try to call them no one answers. I emailed them and no one responded. I am disgusted by this kind of service. I will not pay for something I did not ask for. You can go to hell for all I care