Defy Glass Stove (Factory Fault)

I bought a Defy Glass stove with an Oven at Makro Riversands in late April 2022. The glass stove after two weeks cracked, I then went to Makro Riversands to lodge a complain. They logged a service call with defy who after few days sent a technician from their side to replace the stove. After a week of the second installation, the stove cracked again, followed the same procedure of logging a call with Makro, Defy then sent a second technician from their side to replace the second glass stove. The third Glass stove (Hob) cracked aswell. I followed the same service call procedure again, they sent third technicians with the new Glass stove. After a week the stove cracked again, a week later after logging a fourth service call they sent a fourth technician who came with a new stove. I declined the replacement and stated that I no longer have confidence in the Defy product and brand. After a day I received a call from the Defy call center in which their sales consultant told me they won't replace the stove because of my negligence. I asked the consultant to explain the term NEGLIGENCE, and she couldn't, then started to threaten me with lawyers. I then explained to her that I have been having the same issue with three Glass stoves that Defy replaced directly and had their technicians do the electric installations. If it's due my negligence, why did they send the technician with the fourth stove to replace. If it's an electric negligence, the stove was connected by their technicians three times. Now because I want a refund for the stove they sending me from Pilar to post for five weeks now.