Bad service, poor quality products

I bought a phone - Samsung A20 at MTN mall of Africa the one opposite pick'n'pay clothing towards the end on November 2019. The phone went blank after a week. I took it back to the store as it had a warranty and they told me they would take it for repairs as it didn't have a cover and the screen has scratches. I was okay with that although when buying the phone they didn't offer me insurance on it or even adviced me to get a cover as it would affect the warranty. Phila, the lady whom I bought the phone from and who also assisted me with getting it to repairs filled in the wrong forms which resulted in me not getting my phone for over 1 month now. I still haven't received my phone and the only time I ever get information with regards to it, is when I call to complain. The one time I went to the retail store at Mall of Africa, the staff there were very rude to me and told me I specifically had to wait for Phila, as I was not their customer. I'm very unhappy with the service and I am refused a refund and they also refuse to give me a new and operational cellphone. Its almost 2 months without my phone. I'm not happy with MTN