Bad service

Have a contract with MTN, On 10 November 2020, I booked in my phone at Mams Mall Pretoria as it was faulty .. Was told to pay in R410 for repairs, end of March 2021, but since then no one has called me to update me on what's going on, I'm the one who keeps on calling and still don't get answers as to my whereabouts of my phone. What's irritating is that I'm still paying for something that I don't have...