Store sold my device

I took my tablet for repairs to the Telkom store in Sandton City. After fighting with them for 4 month to get my device back, they called me and told me that my device is back. When I got to the store, they told me they gave my tablet to someone, I managed to get the managers number, who promised to call me the following day with a solution, and he never did. I went there the following day only to find that the store has been closed for renovation, the manager is ignoring my calls. I call the Telkom help line, they told me to call back the same person who is ignoring me. Now I am paying every month for a device that I do not have. This Telkom store has given me the ****tiest time of my life.