No more payments until I have upgrade in my hand

My experience with Vodacom to try and upgrade, has been nothing short of horrific. My question is, how can a company like this still trade and do business?? No word from Vodacom when I try to upgrade, but heaven forbit, just skip a payment and everyone who works for them, will be on your case. So, if Vodacom refuses to get back and assist me, I will simply stop paying. You are now in breach of contract, because I can legally upgrade and you are blocking me to do so. Read carefully.....I AM STOPPING ALL PAYMENTS TO VODACOM UNTIL I HAVE AN UPGRADE IN MY HAND..WHICH IS THE DEAL FOR R140 PM, NOT R249.