Doodgee & cash crusaders Refusing to repair new phone undrr guarantee

I bought Doodgee phone on 23/12/2016,I had problems with the phone after +-4 months.the phone screen over heated and screen showed stripes.I took the phone back to cash Crusaders Somerset mall,and they only supp**** me with another battery stating that this is the problem the battery.again after about 2 weeks the phone did the same thing to which I was losing a lot of customers as I have my own business.in the interim I went and bought another phone from another place to get all my business up to date.I went back on the 3/8/2017 and none of the personnel there took a check list to go through to see if there was any damage on the phone,to which I know it wasn't as I still bought the pouch at them as well.they told me that they will contact me as soon as the phone is back or have any feedback for me .this never happened,I went to them and asked if there is any news on the phone,to which I was informed that the phone has marks on it like it was dropped on the floor?? Now Cash Crusaders and Doodgee is refusing to repair my phone and wants to charge me,but the phone is still under guarantee and there was no check list done with me at the time of handing the phone over to them...this complaint is for Cash Crusaders & Doodgee phone's for misuse of repairing and not checking in detail what the problem is ...the phone must have dropped in eiter the possession of cash crusaders somerset mall & Doodgee ... Please assist with this . Phillip kilian ********** 365