Ackermans Clearwater and their lies - don't ever a phone there!!!!!!!!!!!!!!

I bought a phone June 2017, it stopped working towards the end of November. I took back as it was still under warranty and they told me it will take 21 days. 21 days pasted so in January I went back to enquire about it. I got it back on the 17th of January. The phone was still not working, so I called them and they told me to bring it back. I took it back the Monday. They told me again that I must wait 21 days. I have been calling and asking about the progress but no one can give me a straight answer. I am so frustrated with the different stories that I get every time I call. Today (26 February 2018) I went back again, only for them to tell me that there is no Manger. I don't understand how a store does not have a Manager, (apparently he only comes in on weekends) I am so fed up with this Ackermans Clearwater. I can't get my phone in working condition they can't even explain what the problem is and I have been asking for a refund as I have spent 3 months without a phone that I PAID FOR CASH.