Enticing retention package dishonoured

I upgraded my Vodacom contract in May 2015. I was about to switch to Cell C,<br> who offered me a better deal, when Vodacom retentions offered me a better deal.<br> I accepted the deal, for which their is evidence on paper as well as on Vodacom's recording. Once they locked me in, they proceed to dishonour their agreement, and they are still doing so today, despite many long hours spent with customer \care". They have \""retained\"" me"