Makro complaint: Defy gas hob with defects

I bought one Defy gas hob from Makro Germiston on 18the of September, the coc installer came to me to install the gas hob on 22nd of September, The installer cutted the plug in order to connect the gas hob to main power, after installing it I found the gas hob top has few defects on paint took off. Next day I brought the gas hob back to Makro, I was told my gas hob is out of warranty because we cutted the plug off.

The they changed mind to ask me take the gas hob back home and they will send technician to my house to check. I went to Makro on 27th of September and 3Rd of October to follow up, but the Makro told me same story, one man called Mondale and one lady called Queen was meeting me. I was wondering how Makro can sale the product with defects to me, and they made excuses for refusing to give me a warranty. The gas hob come with defects not because I cutted the plug.