Misleading Sale

Went to builders warehouse in Rivonia on the 28th to buy a gas heater but luck after a long searchbi went to this store , one of the staff members had a gas geater ib his trolly and i approached him and he saud thatnit was the last one so he gave me the heater , told me thatbit was returned but ita working customer didnt want the heater anymore, he sai it was working and he just tested it...... i got home and the heater is not working, mind you in from Midvaal and how i have to go all the way back to builders in Revonia to get my refund