I don't kniw how to explain this disregard for customer satisfaction

They sold me a mobile data contract that doesn't work where I need it to work. Then they cancel it but continue to charge me for it even though they know I can't use it. That's not all.... On top of that they are still charging me for my previous contract that this one has replaced. I was told that someone would call me to discuss me giving the device back and refunding me all the money wasted. Still waiting, never happened. Was supposed to happen 2 months ago. Then their sales agents still call me to ask me if I want to buy more stuff. Ridiculous. I really need mobile data as I travel extensively but now I'm stuck for months thanks to this service provider.