Bad service from a Store Manager very bad

I bought a two plate stove at ShopRite in Braamfisher Soweto, in June one plate stopped working I then went to them to exchange. The stove was exchanged then now at the beginning of December same problem occurred I went to ShopRite to report the matter because the stove still has a warranty, box and the proof of purchase. The store manager *****s Mdaka told me he won't exchange the stove regardless I have the slip,box and the warrant. I asked him about the term of exchange or refund. He said it was explained to me. He took the pictures of the stove he said he will said it to his boss. I then left the stove to the store the following day I went back to the store he said he won't exchange the stove because his boss said so, I requested to see the bosses reply he refused, but he was able to show me the reply of another customer. Mdaka left me standing I had to follow him around. And the stove was not exchanged. Bad service from a store manager, what is he teaching his team members?