cricket lied and screwed me over

I got a call from one of the main guys at the main office to get a free phone when I called cricket 611the guy told me I was going to receive the HTC ONE SV 4G when I gave the phone to the csr at the store she dismissed what he said and gave me something different and ever since I got the phone I been having problems I know cricket records the conversations  but the guy denied what  he had said and I'm still paying full price for a phone that only works 80% of the time if cricket promises something they should go through with it its unprofessional to lie deny and avoid what they did its not like I asked for it that's just what I was told I was going to get and now I'm stuck with this crappy phone that started messing up within a week after I got it and I don't know who to call to fix it