Very bad service

I went to sell my phone to get a cheaper one at the franchise in worshop durban got the phone they showed me it was charging I get home it's not charging and was told that there is no guarantee on the phone upon returning home I notice a small crack when i tried selling another phone they didn't accept it because of the crack they did advised if this is not sorted I am going to the ombudsman this is poor customer service the phone is not charging goes in and off so I wasted my money now I have no phone for people to contact me ***