Violation of consumer rights

Today I took back the faulty electric blanket I bought from clicks despatch on 17 July 2018. The plumpy old white cashier told me to step aside while waiting for the short colored lady to test if the electric blanket is indeed faulty, I felt very offended but remain calm. After 25 minutes of me waiting, the short colored lady came back saying the reason she took longer she was consulting with the manager if I must be given a new electric blanket as a replacement. I fail to understand her statement because I gave her my cash slip that reflects 12 months guarantee from the date of purchase. All this is done in front of other customers, I have never felt so humiliated in my life. As if that's not enough, the colored short lady told me that the new electric blanket guarantee will end on 17 July 2019 meaning in less than a month from today. I asked to see the store policy that support her statement, she left for another 20 minutes and came back with another colored female who introduced herself as a manager and told me that there's no store policy that says that I must just accept what they are telling me. I refused and told them that what they are doing is the violation of my consumer's rights. I told them that I will take this up as I'm not happy about the manner they're treating me. She told me she doesn't care. Can someone assist me before I take this matter further to ombudsman.