Edgars sold me a Faulty product

I budgeted, and bought myself a cell phone at Edgars Cell phone counter in Adderley Street on Monday afternoon at about 17:00 the 2nd Nov. The following day,I noticed that the Samsung phone switches off on its own, I decided to take some time and monitor, mind you, the sales consultant who sold it to me, also struggled a bit with the sim card connection. The morning of the 4th, the phone started rebooting itself all the time. I called the store, they asked if I was using a new memory card or old, I advised that its new and was bought the same day at the their store, they said I must remove the memory card and see what happens, if I have a problem take it back to them in 7days. I removed the memory card, but the problem persisted, I then took the phone back to the store, lunch time the 4th. Now this is my problem, at the store they told me that they need to send the phone for an OBF Assessment ( which I don't have a problem with).. but the process will take 2 WEEKS. 2 WEEKS?. I'm travelling and going on leave next week on Wednesday and I need the New Phone I paid for. They sold me a defective product, why are they making this my problem?? I'm still waiting for their manager to call