Buy & Get promotion

I bought a Samsung fridge and washing machine in Dec 2015. Since then I have been trying to redeem my 4 - 6 tickets on the promotion. It has been 2 1/2 months now. After emailing (since Jan) and calling and following up, I have eventually spoken to someone who has told me that I'll receive my PIN next week. I enquired as to how I need to make my plane bookings (as I've made a specialist appointment in Cpt for the end of March) only to be told that they need 4 weeks notice for bookings. I my problem was resolved and if someone ever got back to me when I first enquired in Jan, this wouldn't be an issue, but I've had to follow up and follow up and now I have a huge problem. Please assist. I cannot change the specialist appointment and need this resolved.