Pathetic service-faulty goods

It has been three months since the upgrade of my phone to a Samsung Galaxy core. the phone has been in to be repaired 5 times the first time round and then they gave me a new phone. 5 days after having the new phone it did the same thing and I took it back and they wanted to offer me a new phone same make a model, which I dont want. I have dealt with the Malmesbury branch where the staff advised that the phone was taken off the shelves due to the make being faulty and numerous clients were having the same issue. I have asked Kirsten in CPT to help and an Elizabeth at the repair centre now wants to give me the same model which I dont want. I will now go to the CPA and will stop my payments as I am paying for a defective product