Bad service

I bought samsung S8+ in April 2017 at MTN customer center in The Glen mall in Johannesburg. As part of promotional package, it was supposed to come with power bank/pack and the phone protection cover. Because I bought it at the time when they launch the first sale of the phone in SA, MTN told me to download the samsung reward application on my new phone and order the promotional package as they have not received it yet. I did and after about two to three weeks, I got the mail from samsung reward apologising about the delivery delays and that they will deliver soon. A week later I left the country for about six weeks on work related trip and came back still without any delivery from samsung reward. I went to MTN where I bought the phone to enquire about the failure to fulfill the sale promotional promise but I was told that they cannot help on that as that is samsung promise and problem to be resolved by them. They said what they can do is to try and contact the with my details if they'll be able to as they don't have their contact but I must try to contact them myself as well. MTN siad they will get back to me if the come right, which never happened and which I guess they never came right. On my side I responded to their previous mail and they sent me a mail with the currier company tracking details, which indicate that the delivery address was wrong and tried to contacted me without success. What I asked them is how can I not get my own adress right unless samsung gave the currier company incorrect address. I then ask them the way forward, and they gave me the currier company contact numbers to follow up myself. The carrier company told me that the package was sent back to samsung, which I notice samsung reward about the feedback that I got from the currier company and they never responded back to me. After several mails requesting them to redpond to my mail, they resend me the same response with the same currier details and I told them we already went through that so I need way forward but they dissapeared again. I went to samsung customer center at 14th avenue in Constentia in Johannesburg to request assistance. The manager there said they are not dealing with that but he will try to assist by contacting them while I was there but couldn't managed to get through. He also contacted the currier company and they gave him the same response they gave me. I'm now really fed up with them because every time I contact them, the give me the same currier information and disappear.