Free airline tickets with a contact on a BlackBerr

I upgraded my contract with a BlackBerry Passport with a free gift offered with it on a promotion, I only received the handset with the Top dog voucher and was told that they will let me know when to collect the free airline tickets, I waited more than a month to required about the tickets, in return they told me BlackBerry is responsible for the tickets, on contacting BlackBerry they have no knowledge of such a promotion, went back to Vodacom, outlet advice me to contact customer service, send mail to them with my query, respond that they will get back to me, waited again for more than a month on their response so I contacted them again, same answer they'll get back to me, at the end of March I contacted them again after no response from Vodacom, they then response to get back to me in 2 days of which has become 2 weeks now, I don't know what to do anymore because Vodacom isn't interested in doing anything as far as I can see. What do I do next