Vodacom lost our phone

We had left our phone for repairs at the vodacom alberton store in new market mall, Upon every visit their new managers and new supervisors who keep rebook in our device buy cannot repair. When we decided we had enough and went to collect our phone we were told it is sold to defray costs however the 90 day period has not expired. We were told that a supervisor would contact us today and nobody has called. The store has lost our device and cannot assist us. Is this the service vodacom want to promote?