Misrepresentation, delivery date failure

I was contacted by a mobile talk representative on 11 December 2015 offering a new Telkom LTE product. Not having caught which company she was calling from, I later asked for confirmation of where she was calling from, at which she rep**** Telkom. Satisfied that I was dealing with Telkom (along with the very detailed information she had available on my current contract with Telkom) I accepted that I was being offered a viable alternative to the current product I had with Telkom. After agreeing to the purchase of the product and having been made aware of the 7 day cancellation period after delivery, I specified a delivery date early in January as I was leaving on holiday the next day. They, however, effected delivery the very next week, to a third party, who was unaware that I was to personally take delivery, and which should have been verified by the delivery company (RAM). On my return I started using the product but was my data exhausted after 5 days. I went to Telkom to return the product, but was only then made aware that I had not dealt with them. Despite all of the above they have been extremely uncooperative in agreeing to the cancellation of this contract.