Cellphone Repair

Hello, I need your assistance, I bought a phone at pick n pay Nkomo Village in Atteridgeville on the 02/05/2020, the phone only worked for 7 day, I then took it for repairs at pick n pay on the 15 May 2020, I still have not received it, I go to the shop almost every week with new excuses from anyone I find on the cellphone section, I went again yesterday and was told they dont know what to do as they have not yet received any communication from cellc. I am always met with unexplainable reasons and promises of them calling me back with an update but I am still waiting for their call. I don't know what to do anymore