what a bad service i have recieved at Foschini Fourway

what a bad service I got from Foschini Fourways. I bought a phone Nokia. on my way home the phone switched off. I thought it needs to be charged. I charged it and it switch on for 5min then switched off again. I took it back to Foschini Phindile promised to call me back which she never did. My husband went to the shop and they told him that they took the phone for asse*****t and when it came back the report say it was damaged by liquid. They did not send the report to me. They told me that I damaged the phone. I asked them how and they never responded. They told me that they will take the phone for repairs and I will be liable for that.