Where is my phone Nokia 3

I have had a contract with MTN for 4yeats now and in November 2019 I booked One of my phones still under warranty for repairs at MTN the Glen shopping mall. They said 14 days but till now I haven't received my phone I've been to the shop several times and they keep giving me excuses. I'm really disappointed and regret upgrading my contract. I don't like to complain but MTN has really pushed me and that was my work phone. I want my phone or I'm involving ombudsman. My name is Alfred Mugano ***