Samsung Gear S2 Watch

I upgraded my cellphone contract at MTN to the new Samsung S7, I was offered the S2 Gear as an add on special to my contract. <br> I decided to take up the offer but was surprised to find that the running app is way out on the distance measure, more than 2 km over a 5km distance. I returned the watch within 7 days and it was replaced with another. Again the measurement was the same, over 2Km out over a 5km distance. I again returned the watch and again it was swapped out with a promise that a Samsung expert would call me to discuss the problem. No call was received. My MTN agent has been superb in her service and keeps following up and telling me that someone from Samsung will phone, but this never happens. I again took the watch back over this last weekend (the third watch) and again they swapped it out for a new one (this is now the 4th watch they have given me, but the distance problem persists and still no one has bothered to call me. What are you going to do Samsung? Give me a new watch every week until you can motivate one of your staff to take an interest in the customer and call me. Samsung's service is appalling.