Fixing a phone takes 4 to 5 months

Hello Edgars I am B Mbele. I wonder how long it takes for you to fix a Cellphone. Normally if you fix your goods on the street they do it right there and then but I am still surprised with what Edgars Maponya Mall is doing to me. I am suspecting that they gave me a dead phone. My story started on the 09 September 2014 when I walked into their store and bought what I thought was a brand new Blackberry Z10. The phone died on me in October 2014 a few weeks after I bought it I took it back and they booked it for repairs and I received my phone again in November 2014 and in February 2015 2 months after it came back from repairs it broke down on me and I took it for repairs again to the same Edgars Maponya Mall. It has been with them since that day the 4th of February to be exact. I have been to the store where I kept getting EMPTY PROMISE that I will get my phone in 3 days' time and now it is 5 months and I am still without a phone. All I need to know from you Edgars is how long do you take to fix your phones? What is it that a Customer must do to get service? Must I buy back my phone from you? Maybe I need to go to NCC to get my phone fixed, I heard their service is free and quicker.