LG not making my Life Good-Frustrating

I purchased an LG G6 at Cell C on 25/09/2017 and the promotional strategy used was getting a R1000 cash back together with the watch. I got the watch when i got the phone. I was told to whatsapp the copy of the contract to ********** 776 which I did and no one responded to me till today. I also sent an email to ********** and still no response. The R1000 cash bach comes from LG. Nobody acknowledged receipt of my request. LG failed to deliver on their promises and if this is how they treat their customers then I will never purchase an LG product.