Call centre agents putting the phone down on you when you decline their offer

For the last three weeks I have been getting calls from various agents claiming to be from Vodacom or their agents. The numbers are either 087 numbers or area code 031 numbers. I get told how I am using alot of data and talk time etc etc. and how Vodacom would like to upgrade/migrate me. When I decline I get given another long list of options and when I decline that the rude woman on the other end of the line puts the phone down on me! Previously another woman decided to argue with me that my settings were incorrect because I dont get any decent reception on my router and want to cancel my contract. Instead of just accepting that I no longer want my contract she chose to argue with me for almost 3 minutes and then proceed to tell me what I should do to stay with Vodacom and not cancel my contract. The instance before that the same happened with a guy calling me to upgrade my data, which costs more than I already pay for something I can never seem to connect to by the way. I have tried to call Vodacom to complain today and have been on hold for the past 10 minutes after I have been transferred from department to department and no one seems to either know what they are doing or couldnt care less.

I understand that no business wants to lose customers and that call centre agents are simply doing their jobs but why Vodacom are they so rude and have such bad attitudes with your customers? If you want us to stay give us reasons to stay not leave even faster. I'm so annoyed with this that I'm ready to cancel ALL my contacts and move elsewhere. Besides the fact that we pay such high call and data rates we now have to be treated with such disdain because we dont accept the supposed wonderful offer Vodacom wants to give us, which by the way will cost you even more than you already pay. Please stop giving my cell number to outside parties and get your call centres to leave me alone before I cancel everything and leave entirely. I've already cancelled my data contract today because I have no reception, dont make me cancel both cell contracts too...