Faulty Phone

I bought an MTN phone Nokia Y5 at Randfontein Sportscene on the 10th of April on the 17th of April my phone started acting up. it Froze, overheating and did not switch on. i took back the phone and told the manager that i no longer want the phone and he said he will send the phone back to MTN and wait for them to tell him what to do.. What guarantee do i have that the phone will not have issues in the future. So i want my money back to buy another brand.