Bad after sales service

I bought a Samsung Galaxy J7Pro at Vodacom at the end of last year. The phone's GPS was not working so I took it to Samsung in The Grove Mall on the 2nd of February. They tested it and found the motherboard to be faulty. The fault was registered (Service no ********** 927) butI had to wait for them to order the part needed to fix my phone. I have made several calls to follow up and spoke to the manager twice who promised (every time) to find out where the part was and to call me back asap. He never did. I then contacted Samsung directly who promised that they will follow up and get back to me by the end of the week. That was almost 2 weeks ago and still nothing. I mentioned to them that as this is a new phone it is unreasonable of Samsung to expect me to wait indefinitely for a part to repair the phone. I wanted to know why the phone cannot be replaced but they seem to be adamant on having the phone repaired instead. Meanwhile, as I am using the phone’s GSP when seeing clients, it is a terrible inconvenience not to have this function working properly.