Cell c - useless

I have had an issue with cell c for over a year now. If I am not in a wi fi zone my mobile data does not register. I have done 2 sim swaps already as according to the technical dept that was faulty. Did as they said and now when I phone back they say it's the tower. Come on now, really the tower is a problem for a year? Well in that case I want to cancel my contract without penalties, as this is not my problem, and change service providers. The assistance you get from cell c is useless! I would never recommend them to anyone! Please can someone assist. My mom has cancer and I need to b contactable when I have to pick her up from treatments. She cannot reach me due to this issue. I'm beside myself with cell c - I just want to be assisted successfully! Kind regards Jennifer Parker