MTN has my phone since 2023

On 2nd May 2023 I took my Samsung Galaxy SlZfold3 cellphone to MTN Thavhani mall for repairs. The quotation for repairs came as R16216.74 which I rejected and asked me to pay R450 for quote rejection fee which I paid on the 22 September 2023 so that they can return my phone back to the store. I was promised that the phone will be returned back to the store which has never happened. I tried to contact MTN several times via email with no luck of assistance instead I was taken from pillar to post till today MTN Thavhani mall has never returned my phone. I have proof of payment for the quote rejection fee and the form I received while the phone was booked for repairs but I have never received my phone back from MTN . The worst part is that am still paying for the phone though MTN Thavhani mall has never returned it to me.