Breach of verbal contract

In December 2015 I was about to cancel my contract which was about to end.<br> A sales consultant phoned and offered me a package (sim only) that contains 1G data and 100min for R100 pm, was a good deal so I accepted.<br> However,I was only getting 150 mb of data, I phoned Telkom and they investigated.<br> After their investigation (I am sure their team had access to the voice recording for the verbal agreement) they still claim that the package does not exist.<br> How can Telkom offer me a package that I agreed to and later state that the package does not exist.<br> I am sure this is a breach of contract on your part.<br> Any legal advice and steps that I could take would be helpful?