No honourinng of R5000 travel voucher on purchase of a Samsung Note 8

Vodacom has a promotion of a R5000 travel voucher on purchase of a Samsung Note 8. The promotion is advertised as running up to February 6. On January 27 I netted into a contract with Vodacom to purchase a Note 8 only to learn afterwards that the promotion has been closed. This is false advertising! The TV monitors in the store boldly displayed details (they still are as of today) of the promotion with the expiry date. I called Head Office to complain and was told that the promotion has nothing to do with Vodacom but is a responsibility of Samsung. this is unacceptable false advertising!! How can they feature the promotion in their flyers and in their stores and then turn around to say that it is not their responsibility?