Warranty rules

On 17 January 2021 I gave in my TV at Hifi Corp because it had this black cloud on the screen and it is still under warranty. 5 February 2021 we followed up with them since we have not heard a thing from them. they informed us that they still busy with the repair and we must come back on 14 February 2021. On 14 February 2021 they informed us they will replace the tv but they do not have stock, but there are three of those tvs on the truck and it will be there by 17 Feb 201. On 17 Feb 2021 still no TV and they told us it will only be in on 19 Feb. I phoned the branch on 19 feb and spoke to the manager he did not even know about my tv and he informed me he does not have stock but he will get it from another branch and i can come and collect my tv today (22 Feb). Just to be phoned and tell me he could not find a tv for me and ill have to wait until he gets me one. He also made it very clear that he is losing money on this tv because I bought it on a special. I just would like to know we us costumers must understand and comply to their rules and regulations but when it comes to hifi corp the do as they please, WHY?