Bad attitude and refund refused

I bought a product called Pest control at Homemark based at Festival Mall. I wasn't happy with the product so I returned it to the shop , I tried to explain to the sales lady called Rejoice that I lost the receipt . She was so rude and beyond control . When I first bought the product she gave me a receipt that looked like a invoice not a normal receipt with terms and conditions . When I tried to tell her that I wasn't happy with the product and that I wanted my refund she told me that since she was the manager and shop owner she has the right to refuse me with my refund , that the only option I have is to take another product . I left the product there in the shop because I called the head office and I spoke to Sifiso who promised to speak to the area manager to sort it out but I still waiting . That sales lady needs training on customer services. Please assist to get my refund .