Promise to replace cellphone

I purchased a new i Phone 4S from CNA ERM 3 weeks later it was faulty took it in and was told it would be send for repairs. after 2 weeks went to go see if my phone was returned and was told that they had phoned me 3 times to tel me it went to the incorrect supplier, after questioning the lady found out she was lying and did not attempted to phone me. Was promised my phone would be fast tracked witch i was **** about again. I demanded that the phone be replaced as I could not wait another 6 weeks. In the course of 7 hours Michael the store manager contacted me 3 times to say I must just bring the cellphone box in and he will replace it . after witch he would call me and say sorry but he cant CNA cant take that type of loss this he did to me 3 times over a course of 7 hours in 1 day. according to the consumers protection act I can ask for a new phone or be credited according to Michael its not that easy and CNA doesn't have to