samsung trend now phone

I bought a Samsung trend neo phone on the 24 December and I soon realised that it was not functioning properly it kept saying \SIM rejection, phone needs to restart to detect sim\". I took it back to the store where I bough it on 5 January 2016. I got it back two weeks later and it was not fixed, instead it was worse and the report said that there was no problem with the phone. I took it back few days later and they took again to repairs. It came back after a week with the same problem, this time they had not done anything, and the report still said no problem with the phone. I felt stupid and disgruntled by this. I took it for the 3rd time for repairs to Vodacom repairs centre in Pretoria CBD and they told me some long story and booked it in again. Mind you I needed the phone especially the internet and the phone they gave me to use for the time being was some useless out dated phone. Ten days later I went to collect my phone from repairs. IT STILL HAS THE SAME ISSUE. IM MAD AND DISAPPOINTED BY SAMSUNG. IT MEANS I NEED TO TAKE IT BACK AGAIN FOR REPAIRS FOR THE 4TH TIME. THE WOLE OF JANUARY AND FEBRUARY I WAS WITHOUT A PHONE YET I BOUGHT A BRAND NEW PHONE END OF DECEMBER. "