Disgusting service

Angry Customer -I went to hi fi Cooperation to have my television replaced as it is still under warranty. Yesterday when I arrived at home after working a late shift I tried to switch it on and it started showing lines. This morning I took my television to Hifi Cooperation in N1 City Mall at about 09:52. I was assisted by a gentleman called Michael, who tested my television and said it broken ,I was not happy with the feedback I have received ,and I asked to speak to the store manager,He call Mariska who happens to be the store manager I explained my side of a story to her and up to my surprise she told me the television is broken without even plugging it and there is nothing they can do yelling at me in front of other customers when I asked if I can get the terms and conditions of their warranty .I felt so humiliated and disrespected and believe it is within my rights to ask questions but I guess in this store customer right are violated .The last words she uttered is that are you still waiting?I think you will wait here until 17:00pm which is closing time for them.I left my television with them and still want my replacement.