Lost luggage in an Uber ride

I am very disappointed with how Uber has handled my issue. I reported that I was having problems reaching a driver named Siyanda Mngxati. I rode with him on Saturday, 17 February 2024 to Jo'burg & back to Kempton Park. Amid everything that was happening, I left my luggage in the boot of his car. I called him immediately when I realized I left the suitcase & he promised to return it... I have been in contact with Uber since Sunday, but till today, I still have not received my luggage and Siyanda's phone has been off ever since